CVRomhacks

Essentials

Castlevania 2 Retranslated by Bisqwit + Double Hearts Rate + Palette Improvement:
The latter two are self explanatory, double hearts to stop the game from wasting your time and color improvement over the drab original.
Bisqwit's retranslation is too big of an overhaul to talk about here, it's the most elegantly re-written hack I've seen of CV2 and overhauls the menu and tip system as well as adds in-game save system and map of the game. I recommend to go even further and use scarletspiderdave's LUA script in the FCEUX emulator as that adds stuff like improved enemy ai (skeletons turn around) new boss patterns and bosses don't respawn as well as a helpful debug mode for when the game is often too bullshit to bear anymore.

Akumajou Densetsu(J) - Castlevania 3 Relocalized by ShadowOne333:
You know by now everyone knows to play the japanese version of CV3 for the music and uncensoring but this is the one you want to play imo. I'm afraid people are opting for the original fan translation which keeps shit like "Ralph Belmondo", it's way too literal a translation. Shadow's is essentially a new, faithful localization that goes even as far as to redraw Alucard's sprite to match his SoTN look and it's awesome.

Konami Collection Vol. 1 & 4 (E) - Castlevania Adventure & Belmont's Revenge Speedhack Autoboots:
These next two are special, little known fixes to the bad gameboy games that puts them closer to the level of the NES original. The massive slow pace is completely fixed, they play more like the original games. To add to that, these are collections of Konami gameboy games that were updated for gameboy color so you'll get to enjoy them with a new 'DX' look as well. If nothing else, people who are asking which CV games to play, Belmont's Revenge is fucking worth it for the music alone. It's genuinely great and well designed. This hack also exists for Castlevania Legends but it's not included cause that game SUCKS!

Castlevania Harmony of Dissonance - Palette of Dignity + Juste Changes:
This one fixes the god awful color palette and also attempts to unfuck how dumb Juste often looks. No more blue outline and his default pose is the classic Belmont stance as well as other animation changes.

Castlevania - Dawn of Sorrow - No Touch Screen + Fixed Luck:
An absolute must; fixes a major oversight that prevents Luck from affecting soul collection and completely removes any touchscreen interaction.

Extras

Aria of Sorrow Fix 2:
Typo and series consistency name fixes

Castlevania Bloodlines - Color Hack:
Self explanatory, this one's pretty extra but the author paid a lot of attention to series canon here, Eric's sprite actually shows his blonde hair instead of green and other such corrections.

Castlevania Portrait of Ruin - Typofix:
Self explanatory, 'RICHITER'

Kid Dracula (U) - Restoration:
Restores missing graphics like church bell and manji (japanese 'swastika'), this is the gameboy port/semi-sequel

Bonus:

Contra Hard Corps - Enhancement + HP Restoration:
Hard Corps as it was meant to be played! JP health restored with many quality of life fixes.

Download:
https://www.dropbox.com/s/t7whn8wo29u72nk/CVRomhacks.zip?dl=0