How I have considered each TM:

Power - How useful is the move and what's its purpose?
Availability - How easy is it to obtain and are the methods of obtaining this TM/HM worth it?
Accessibility - How many different Pokemon can learn it and is there a viable use for those Pokemon to learn it?
I have taken into account unavoidable glitches such as the Badge Boost Glitch and glitches associated with moves such as Psywave, Bide, Body Slam, Rage etc.

The tiers:

S: These moves are completely broken, meaning that not only do they have no drawbacks, they're overpowered to the point of unfairness.
A: These moves are outstanding moves with no drawbacks, but not completely broken like S-tier moves are.
B: These moves are great moves which should find themselves on a lot of Pokemon's final learnsets, though there are a couple of minor drawbacks.
C: These moves are solid and could find themselves on a lot of Pokemon's final movesets, generally as a solid 3rd or 4th choice move. Most of these are solid mid/end game with a few drawbacks.
D: These moves are usable at some point during your playthrough, be it during a certain portion of the game or a move you turn to when you are in a sticky situation, but you shouldn't have any of these on your Pokemon's final moveset.
E: These moves are completely useless and in most cases, should never be taught to your Pokemon.

**S Tier:**
Double Team - I hate evasion moves as much as the next person but not only does Double Team raise your evasion stat, it also raises your other stats due to the badge boost glitch. Can be bought at Celedon Dept. Store and almost any Pokemon can learn it.
Swords Dance - Boosts the Attack stat by two stages whilst boosting other stats due to the badge boost glitch. Quite a few Pokemon can learn it and the TM can be found in Silph Co. which you have to enter to complete the game.

Mimic - Mimc in other gens is a fairly situational move as it will only allow you to mimic the last used move of your opponent. However, in Gen 1, it allwos you to mimic any move in your opponent's moveslot. It is a little out of the way as you need to backtrack to Celedon and buy the Poke Doll to obtain this TM, but it's more than worth it. Furthermore, most Pokemon can learn it, making it a must-have move on any Pokemon's arsenal.

Psychic - Psychic is the most powerful type in the game and this move is the most powerful move of its type. Not only does it have 90 power, it has a 30% chance to lower the Special stat of the opponent and can be obtained easily by visiting Mr Psychic in Saffron (an area you need to visit to complete the game).

**A Tier:**
Body Slam - This move is in the gray area between A and S but the reason why I have included it in A tier is because I don't believe it's  as gamebreaking as the other 4 moves are. However, what Body Slam offers is 85 power, a 30% chance of paralysis if your Pokemon's type is different to that of the opponent and a move a lot of Pokemon can learn. You have to defeat one extra trainer on the SS Anne to obtain this TM but it's more than worth it as it serves a purpose throughout the game and could be used as your Pokemon's staple move even in the Elite 4.

Thunderbolt - A 95 power Electric move that's given to you for free by the 3rd Gym Leader and arguably the best Electric type attack in the game. This move can also be given to many Special Attackers or Pokemon such as Muk to give them a bit of extra coverage.
Dig - Another move that is given to you for free. Whilst you could argue Dig has a drawback due to it being a two turn attack, I believe this is just a minor inconvenience and indeed, the first turn allows you to avoid a hit from almost any move. A lot of Pokemon can learn it and it has 100 base power.

Earthquake - Earthquake is essentially the same as Dig but without it being a two turn attack. I would rank Dig just above Earthquake due to being given the TM for free and more Pokemon being able to learn it. Earthquake can be found in Silph so it's not out of the way to get either.

Blizzard - Whilst Blizzard does have a chance to miss, its accuracy of 90 means that it is still a fairly reliable attack and offers that chance to freeze, alongside a whopping 120 base power. This move can be learned by almost every Water type and is a must-have for the Lance fight. This move is found in Celadon Mansion and you have to walk past this TM in order to get the Mansion Key, so it's well worth picking up.

Ice Beam - Ice Beam may be more accurate than Blizzard (and indeed it still offers a base 95 attack) but I do still feel like Blizzard is the slightly better move. Ice Beam can also be learned by most Water type Pokemon and is obtained much earlier than Blizzard at the Celedon Dept Store.

Surf - Base 95 Water move. The only downside is that Surf can never be forgotten once learned but why would you want your Pokemon to forget such a powerful move? This move also provides coverage for Pokemon such as Lickiting and Snorlax, allowing them to hit opponents with a powerful Water type attack.

**B Tier:**
Fire Blast -  A move given to you for free by the 7th Gym Leader and in most cases, this may be the only Fire move your Pokemon is able to learn. Fire Blast offers a 120 base power with 85% accuracy. The major drawback with Fire Blast is the fact that Fire type moves just aren't that great in the game. Fire Blast is a good move to use against some of Lorelei's Pokemon and perhaps against the Champion's Exeggutor or Venusaur but it can be situational.

Rock Slide - Just like with Fire Blast, Rock Slide may be the only Rock type move your Pokemon can learn and indeed it's the strongest Rock type move in the game. It's easily obtained in the Celedon Dept. Store and offers a 75 base power and 90% accuracy. It's given to you early enough that it can be used in a few major fights (Rival, Blaine, Lorelei, Champion) but it's just not powerful enough to warrant it being any higher than high B.

Explosion - Explosion is arguably the strongest attack in the game in terms of sheer power, with a whopping 170 damage which also halves the opponent's defence (essentially making it a base 340 attack). However, it's single use and the user always faints when using it. Despite this major drawback, its sheer power warrants it being in the B tier, but no higher.

Reflect - Reflect increases the user's Defence stat whilst out in battle and unlike other gens, Reflect's effect does not go away until the user switches or Haze is used. I don't believe Reflect has any impact on the badge boost glitch, plus it's based in Power Plant which is a little out of the way to get, but it is worth that effort to obtain this TM.

Substitute - It's very hard to rank Substitute as the move is arguably S tier (and probably even better than Double Team), however obtaining Substitute has the major drawback of needing 7700 coins from the Game Corner to obtain it. And you have to ask yourself - is it worth spending all your coins or wasting hours on the slots for this TM? Is it needed to complete the game? And my answer to that would be no.

Hyper Beam - Again, the move itself would be ranked a lot higher if it was easier to obtain (it's in that grey area alongside Body Slam between A and S tier for me). Yes, it does have that "drawback" of having the recharge turn but in gen 1 only, if Hyper Beam knocks out your opponent then the move skips the recharge turn, making it a 150 power move that obliterates opponents. However, is spending 5500 coins at the Game Corner really worth it to obtain this TM? Again, I don't believe that it is.

Double-Edge - Double Edge has a powerful 100 base power, is obtained fairly easily in the Rocket hideout and, in certain circumstances, could be the most powerful move a Pokemon gets (think Oddish for example). Despite the recoil, Double-Edge is a solid move that can feature on many Pokemon's learnset and for that reason it finds itself in the B-tier.

Strength - If you require a strong Normal type attack and have already used up your Body Slam TM then Strength is a reliable alternative. Sure, it offers no side effects such as paralysis and it cannot be forgotten once it's taught, but with it being a respectable 80 base power and the fact it can be used over and over again, you could do a lot worse than having Strength on your Pokemon's arsenal.

Tri Attack - Now it was difficult to determine whether I should rank Tri Attack over Strength due to the side effects that Tri Attack offers. I do believe that Tri Attack is the better move. It boasts an 80 base power, just like Strength, and provdes side effects in having a 10% chance to freeze, paralyse or burn the target. However, the fact that Strength can be learned by more Pokemon puts it just above in my view, and I am looking at accessibility when it comes to my tiering and most of the Pokemon that can learn Tri--Attack are not strong physical attackers.

Selfdestruct - Essentially just a weaker Explosion that has a 130 base power whilst halving the opponent's health (making it essentially a 260 base power move). You may be wondering why Selfdestruct isn't directly below Explosion, but the fact that all the Pokemon that can learn Selfdestruct can also learn Explosion makes it a bit redundant. You don't need access to both moves on the same Pokemon, nor do I believe you need two Pokemon who need access to a last resort move in your team. Still, it's powerful enough to find itself in B tier.

Mega Drain - What is a 40 base power move doing in the B tier, you may ask. However, Mega Drain is obtained by beating Erika's gym and gives Pokemon such as Butterfree, Beedrill, Gengar and Arbok that much needed coverage against Rock and Ground Pokemon, whilst also being a useful mid/end game move on various Grass types. And if you include the fact that this move restores health, I think it's worthy of its B tier placing.

Toxic - I am a fan of Toxic. A lot of Pokemon can learn it, it's given to you by beating Koga's gym and it's a move that racks up damage the longer the opponent is in battle. If this tierlist was ranking moves in terms of competitive viability, Toxic would be near top of the list. However, to beat the game, Toxic isn't required. It's a useful move, sure, but when you get access to so many strong moves via TM, I feel like Toxic would only be needed in certain situations (plus it's 90% accurate). Toxic is in that gray area between B and C but it's accessibility keeps its head just above B-tier's waters I reckon.

**C Tier:**
Thunder Wave - Another status move. Thunder Wave is learned by a fair few Pokemon that do have a use for it (Wigglytuff, Clefable, Chansey for example) and is fairly easy to obtain, being found near Cerulean City. I can see a use for this move in the early/mid game to paralyze opponents and halve speed, but in a game where physical attacks, stat increasing moves and sleep-inducing moves reign dominant, Thunder Wave feels like a move you'd keep on your Pokemon as a solid 4th slot towards or during the endgame.

Dream Eater - A very powerful move that if used in conjunction with Hypnosis, can be gamechanging. 100 base power, Psychic type and heals up the user in the process by half the damage taken, what's not to like? The problem with Dream Eater is that it can only be used if a Pokemon is asleep and so few Pokemon have a use for it (the Gastly and Drowzee line only). That said, this move is deadly when combined with Hypnosis, which both those Pokemon learn, but that move is also only 55% accurate.

Bubblebeam - Bubblebeam is unlikely to be a move that features on your arsenal towards the endgame, but it certainly offers a use in the mid-game (until Surf is obtained anyway). Slap it on your Squirtle or give your Rattata, Clefairy or Jigglypuff coverage to deal with the many Rock-types in the early game and you can't go much wrong. Bubblebeam is obtained by beating Misty (meaning you can't avoid it) has a generous 65 base power and a chance of lowering the opponent's Speed stat. Good, solid move.

Seismic Toss - Now Seismic Toss is an interesting move. It's a Fighting type move that deals damage akin to the user's level, however it can also hit Ghost-type Pokemon and for Pokemon such as Machop, it can be the only way it can damage the Pokemon that frequent in the Pokemon Tower. It definitely serves a purpose throughout the game and could even be used as a last-resort option, either if your Pokemon has a poor attack stat such as Chansey or if your Pokemon has had its Attack stat severley reduced. This move should not be overlooked.

Horn Drill - OHKO moves are a subject worthy of hot debate, I get that. However the fact that they can turn a battle on its head means that I can't justify putting them in D-tier. I am ranking Horn Drill over Fissure as I believe it's learned by Pokemon that need the move more. If you are not aware, OHKO moves only work if your Speed stat is higher than that of the opponent and your level is higher, and the Pokemon that can learn Horn Drill tend to be faster than those that can learn Fissure.

Fissure - I feel like I've explained Fissure in my Horn Drill reasoning. It's close between the two moves though.
Mega Punch - Mega Punch can be found in Mt Moon. It is a little out of the way, being in a dungeon that you don't need to access to beat the game, however it offers a strong Physical type attack that you can stick on a Pokemon in the short term until Body Slam is obtained. Mega Punch is a solid 80 base power move with an 85% accuracy, making it a solid, if unreliable move to use in the early to mid-game. This move can also be bought at the Celedon Dept. Store if needed, giving it unlimited uses.

Fly - The third HM on this list. Fly is the third strongest Flying attack in the game, which isn't a badge of honour given how weak most Flying-type attacks are. Fly is a two-turn attack, however the user is immune during the first turn. Fly has a resptable 70 damage, a 95% accuracy but cannot be forgotten once learned. One major drawback I can think of is Fly is that only Pidgeot really benefits from it. Fearow learns the much stronger Drill Peck through level-up and Dodrio learns Tri-Attack which, whilst not a Flying-type move, is better than Fly. That said, it can still be a useful move.

Solarbeam - Perhaps a move people expected to be higher on this list, but I can't look past the glaring drawback of this move being two-turn. Solarbeam has obviously gone onto become a staple move within the Pokemon franchise and one of the most powerful moves in the game (offering Fire type moves that coverage to take down Water type foes as well). Even though Mega Drain is much weaker, it heals back health and is a single turn attack. I just don't see a reason why you would teach Solarbeam over Mega Drain (and Grass Pokemon will learn better moves such as Razor Leaf, Giga Drain and Petal Dance through level up anyway). Perhaps I'm being harsh, but Solarbeam belongs in low C tier for me.

Swift - Swift is a basic 60 base power Normal move that can be learned by most Pokemon. It's unremarkable but not unreliable (Swift ignores the 1/256 glitch, meaning it always hits). Not much more needs to be said, it's easily obtained and is arguably Scyther's best attacking move.

Rest - Rest is a double-edged sword. The fact you can snooze off any status inflictions whilst returning back to full health is great. However, Rest leaves you unable to attack for 4 turns (the 3 turns you are asleep and the one turn you wake up) meaning you have likely taken just as much damage as you have slept off during those turns. However, given how unpredictable the AI can be, Rest can still be a useful move to use despite this major drawback and can be learned by almost any Pokemon.

Mega Kick - The reason why Mega Kick is a few places below Mega Punch despite being a stronger move is due to how late in the game it's obtained. Sure, Mega Kick is a 120 base power move, but it's also 75% accurate and is found hidden in Victory Road. Given how established most Pokemon's move sets are at this point in the game, Mega Kick isn't worth going out of your way for, but it could serve as a powerful 4th move if you need one.

Submission - The strongest Fighting attack move in the game in terms of power, however Fighting type moves are pretty awful in this game (as is the Fighting type in general really). Submission is an 80 base power move with 80% accuracy that deals recoil damage and coupled with the fact that it's obtained so late makes you question whether it's worth teaching this move to your Machamp or Primeape or rely on the much better Strength, Body Slam and Earthquake instead?

Take Down - Essentially a weaker Double-Edge, which is less accurate and still deals recoil damage. Take Down is actually obtained later than Double-Edge so why would you use it? It's powerful enough to scrape a C-tier rating but if you're considering ever using this move in the endgame then you're in trouble.

**D tier:**
Thunder - Yes, Thunder is the most powerful Electric type attack in the game, but that 120 power comes with an awful 70% accuracy, plus you have to go out of your way to go to the Power Plant to obtain it. And the cherry on top is that you're gifted the objectively better move Thunderbolt much earlier in the game. I feel like Thunder should only be considered in a last-resort situation, either you need another Electric type move on one of your Pokemon or you're playing a Nuzlocke and your Thunderbolt spammer has died. That's why Thunder sits at the top of D-tier, but it is still D-tier all the same.

Skull Bash - You may be surprised but a fair few Pokemon can actually learn Skull Bash via TM. 100 base power, 100 accuracy. It is a two turn attack which you should only use in the most extreme of situations but it's not completely useless.

Water Gun - It's very strange that Water Gun is a TM in this game but it does give you a usable Water move in the short term until you are able to obtain Bubblebeam. That alone makes it not completely useless, hence it's D-tier ranking.

Sky Attack - The most powerful Flying attack in the game and yes, it's a two-turn attack. The user glows in the first turn then BANG! the move may have missed due to its 90% accuracy. There's just no reason to use this move over Fly and the Pokemon that can learn it don't have a need for it either. Sky Attack is situated in Victory Road in the first room. To obtain this move, you have to push a boulder and whichever way you push it blocks one of the item balls. One leads to Sky Attack and the other leads to a Rare Candy. I know which I'm picking.

Soft-Boiled - An incredibly useful move that allows the user to restore 50% of its health. The downside, only the extremely rare Chansey and Mew (which can only be obtained via a glitch so I'm hesitant to consider it) can learn it. The move itself is probably B-tier, but are you ever going to be in a position where you can use Soft-Boiled on a Pokemon? Probably not.

Metronome - This move is completely random. You use it once and it gives you Hyper Beam. You use it again and it gives you Rage. The fact that Metronome can allow you to use a usable move means it cannot be in E-tier and it is a fun move to use. That said, you shouldn't really use it in any major battles or serious playthroughs.

Dragon Rage - I was actually considering putting this move E-tier due to needing to spend 3300 coins at the Game Corner in order to obtain it. However, it is a useful move, being a set 40 damage move. It's definitely not worth going out of your way to get Dragon Rage, but it can still serve a purpose.

Flash - Again, Flash is another move I considered putting in E. It's an inaccurate accuracy reducing move (which hits 70% of the time) that you need to go out of your way to obtain (you don't need Flash for Rock Tunnel, it just makes it a bit easier to navigate). However, if Flash hits, it does obviously lower accuracy, which can be game changing and it's the only accuracy-reducing move that quite a few Pokemon can learn.

Bide - I love Bide, it's my favourite TM. Bide is an extremely gimmicky and buggy move and I won't go through all the semantics but essentially, it's an attack which lasts between 2-3 turns and any damage the user has suffered is dealt back double. Don't get me wrong, Bide sits in that gray area between D and E, but Bide can actually hit Ghost types in Gen 1, and in a situation where you have an Eevee or Pokemon who only has access to Normal or Fighting moves in Pokemon Tower, it's the only way it can deal damage to the Gastly's and Haunter's that frequent the area.

**E-tier:**
Cut - Essentially a slightly more powerful Scratch but 95% accurate and cannot be forgotten. Cut can be a hinderance, especially if you are a new player and don't know how HM moves work. The drawbacks of Cut being a HM and it being a weak, inaccurate move sees it king of the garbage pile that is E-tier, and wears the medal of being the worst HM move in the game with shame.

Egg Bomb - Only three Pokemon can learn this move (discounting Mew) and none of them need it. Sure, it's a 100 base power move, but Exeggcute and Exeggutor get access to Psychic, Solar Beam, Mega Drain etc. and Chansey has such an awful Attack stat that Egg Bomb will still do pitiful damage. Oh, and it's only 75% accurate.

Razor Wind - I'm not going to get drawn into the debate of why Razor Wind isn't a Flying-type move but even if it was, it's still awful. It's a two-turn attack with 80 base power and 75% accuracy. There is no reason to ever use this move.

Pay Day - The only pay day you're going to get from this TM is when you come to sell it at the Poke Mart because why would you teach your Meowth or Persian a 40 base power move when they learn it through level-up anyway?

Counter - Now if Counter worked in the same way as it does in future gens, then it would find itself higher up on the list. However, Counter only works if the opponent uses a Normal or Fighting type move, making it very situational and overall, pretty useless.

Psywave - Psywave is a very strange move. The damage it deals is between 0 ad 1.5x the user's level and it's only 80% accurate. Psywave did have an interesting premise and could have been a unique move had it been thought about a bit more. However, in this game it's a terrible move that can actually deal zero damage due to a glitch.

Whirlwind/Teleport - Grouping these two together as they're both useless in trainer battles.

Rage - What's worse than a useless move? A move which actively hurts the user. Rage is a 20 base attack move which  deals more damage every time the user is hit. This move is so bad that it can cause softlocks. I have no idea why so many late game Pokemon know this move. Also, if Rage misses thanks to the 1/256 glitch, it means that Rage will only hit 1/256 times and remember, once you use it, you are locked into using it.