I'm a big gamer, and I've had luck with my x800xt p.e. for a good while but the fan died. Instead of replacing it I want to buy a new card... I'm looking to spend preferably below $200. So far I've narrowed it down to a x1950GT, but from doing research on these forums, would a 2xxx series card be better? Any suggestions?
The X1950GT will be overall a bit faster then an HD 2600XT according to the Tom's Hardware VGA charts, but you may want to check individual performance for the games you play most. I would personally choose the X1950GT, as it seems to have a better price that I've seen compared the HD 2600XT, and offers more performance.
I'd go for an x1950Pro over the GT - though they may be hard to find now.
As for 2xxx, you mean 2600? IMHO you'd still be better off with the x1950Pro.
You didn't say what the make of your PSU was or what its rated for on the 12v rail(s) - your probably ok with the 500w unit but post that info just to be sure.
A 7800GS is not any faster than what he had as his card is a tad higher clocked and equal performing to the X850XT. So rule out 7600GT and X1650Xt too. X1950 pro > HD 2600XT = X1950GT IMO. The X1950GT would win with FSAA, the HD2600XT often win without FSAA. The X1950's are likely not going to run on 22 amp 12v though. ATI recommends 30 amp, and the HD2600XT uses less power.
@OP: Regarding 512mb vs. 256mb cards. Generally what testing shows and what I think most people will tell you is that it really only matters if your running above 1280X1024 res on your display. I've found though that on games like Oblivion (texture heavy) it makes a difference even at 1280X1024 (at least it did for me - I originally had a 256mb x1950 and can see/measure a difference with the 512mb). So I think its worth it if you play a game like Oblivion and your at or above 1280X1024.
I agree with pauldh about the power though - if you've only got a single rail at 22amp, you're probably on shaky ground. I've seen write ups that show the card drawing about 9-10amps under 3D load (not overclocked) - so that would leave about 12amps for the rest of you system. If the PSU is older and not one of the better quality makes, you'll probably be less then that. It may work - but you could have problems either immediately or later down the line (which will be hard to figure out!). Safer bet is to upgrade the PSU if you go for the x1950Pro.