At the moment: The F-35A costs $124,000,000. However, at full rate production, that price is expected to drop to $83,400,000. Let's see how that compares to other modern fighters

F-22:$150,000,000

Eurofighter Typhoon: $109,900,800

Projected PAK FA: $100,000,000

Dassault Rafale B: $95,600,000

F-35A projected: $83,400,000

F-16E: $80,000,000

JAS-39: $68,900,000

F-18E/F:$66,700,000

Su-35S: $65,000,000

So, now let's discuss performance. While Kopp and Sprey seem to have flooded the internet with misinformation about the F-35, there do still exist facts

To quote Carlo Kopp

>Hurrr durr the F-35 is too hebby

F-22 empty weight: 19,700 kg

PAK FA empty weight 18,500 kg

Su-35S empty weight: 18,400 kg

F-18E/F empty weight: 14,552 kg

F-35A empty weight: 13,300 kg

Eurofighter Typhoon empty weight: 11,000 kg

Rafale B empty weight: 9,770

F-16E empty weight: >8,570 kg

JAS-39 empty weight: 6,800kg

In another famous quote of Carlo Kopp

>Hurr durr can't turn

Simple loaded thrust to weight is somewhat deceptive here because the F-35's enormous internal fuel tanks are meant to make up for the lack of wing tanks as an option because they compromise stealth. Because of this, the intention is to fill the internal tank variably. So, let's compare thrust/weight while carrying 10,000lbs  of fuel.

F-22: 1.23

Su-35S: 1.13

F-35:1.07

Eurofighter Typhoon: 1.05

F-16E: Less than 1.01

Rafale: 0.988

F-18E/F: 0.97

JAS-39: 0.76

Thrust/weight is the single most important factor in determining agility.  The second most important is is lift loading (not wingloading) which is improperly discussed with respect to the F-35. A good explanation of this is here: http://pastebin.com/k0AsgH6A. After that it's drag. The F-35 does not do shabbily at all on wing loading, though it's certainly not the best around. It will have lower drag in combat configuration than anything but the F-22 and PAK FA (unclear with those) because it will fly in clean configuration.

So, what makes the F-35 a great fighter?

1) Stealth.

Stealth is widely misunderstood. It is not radar invisibility, it is radar visibility reduction. Radar detection range is proportional to the radar cross section of the target. The lower the RCS, the shorter the range it can be detected at. Stealth is lowering the RCS of your airplane to make it hard to detect.

The F-35 is the second stealthiest aircraft of all time, with an RCS estimated at 0.001m^2, slightly better than the B-2 Spirit. This means that it will be detected by radar at 1/10th the range of a traditional fighter radar target. Putting that in perspective, a radar like the F-16E's AN/APG-80 will detect a traditional fighter target at a range of 194km and the F-35 at a range of 19km.

2)Radar

The F-35's AN/APG-81 radar is simply unrivaled. In addition to an incredible regular operating range (>250km for a 1m^2 rcs target) it has electronic warfare and passive detection capabilities. It's massive 70 degree azimuth gives it a tremendous field of view. It's simply the best air-to-air radar around, bar none.

3) IRST

While details are scarce, the F-35's AAQ-40 IRST/FLIR is likely one of the best sets around, with common estimates placing its detection range at 100km for head-on targets

4)Countermeasures

The F-35's AN/ASQ-239 Baracuda suite is a upgrade to the Raptor's AN/ALR-94 RWR. In addition to being able to detect and locate threats from any direction using their own radar, the Baracuda suite contains IR and RF countermeasures, including deployable decoys and jamming modes using the AN/APG-81 radar.

5) MAWS

The vast majority of air-to-air kills in the Gulf War happened because planes were hit with missiles they never saw coming. The F-35's AN/AAQ-37 distributed aperture system, using 6 infrared cameras to give the F-35 a 4pi str infrared picture of the area around him, makes it impossible for missiles to sneak up on the F-35. While there are other MAWS systems on the F-22, Rafale, and PAK FA, the F-35's is the only one that offers true 4pi coverage. It's gonna detect any missile launch and give the F-35 the ability to respond

6) Sensor fusion and the HMD

Basically, the plane automatically combines the data from all the aforementioned sensors and feeds them to the pilot at once through a helmet mounted display. DAS and EOTS will also allow the pilot to "see through the walls" by connecting camera feed to the helmet mounted display. They also provide pilot night vision.

7)MADL

The F-35 has the most advanced datalink in the world. Because of this, ti will be able to share all of its sensor data with other F-35's (augmenting the advantage of sensor fusion. The MADL is faster than the existing Link 16 system, and stealthier and more jam resistant to boot. It can also be used to offer midcourse targeting corrections to the AIM-120D and AIM-9X missiles, which brings us to

8) Long range BVR capability

The AIM-120 has a historical combat probability of kill on use of 85% (11 kills for 13 shots). The new AIM-120D has a range in excess of 180 km, and can receive midcourse updates from the F-35's sensors.

9) High-off-boresight targeting

At closer ranges, the F-35 can fire its AIM-9X missiles in any direction using their lock-on-after-launch and datalink capabilities in concert with its EODAS system. This makes much of the close-range maneuvering that could potentially happen moot.

Forreal, don't believe the media trash on this. "Overbloated defense project is awful" sells like hotcakes. Here's a piece from 1979 about the F-16 right as it entered service

https://www.youtube.com/watch?v=PkrtxDdaWuM

Notice how familiar those criticisms sound? Yet I doubt anyone would call the F-16 a failed fighter

A note on air-to-ground

This is simply an arena where the F-35 is unmatched. With the world's best FLIR, the world's best SAR, incredible stealth, EW suite, and a massive 18,000lb payload the F-35 simply can't be beat for interdiction, strike bombing, SEAD, and anti-armor missions.

It's unmatched in quality in CAS, though the MQ-9 beats it in price.

>Hurr durr muh A-10

The GAU-8 simply isn't an effective weapon anymore. It cannot piece the armor of third generation MBTs. The A-10's magazine contains 1,174 30mm rounds providing 16.7 seconds of continuous fire. Since the rounds cost $50-100 each, this costs $58,700-117,400. For that price, you can buy 2-4 GBU-31 JDAM 2000 lb GPS bombs or 1-2 AGM-65L Maverick laser guided missiles

>B-b-but muh armor

The A-10 only needs armor because it flies so slow. The AAA and SRSAMs that plague it are ceiling'd at 11,000ft. The A-10 needs to descend below this because of its lack or radar or FLIR. The F-35 and MQ-9 do not.

It's also worth noting that of the aircraft I listed at the beginning of this post, the F-16E and F-18E/F are the only other aircraft with real comprehensive A2G capability.

I didn't provide sources in this comment, but I'll cite for data if questioned on it specifically. I can also answer anyone's questions on the subject.