"Best prerformance for the price"5.0 starson by AuroraAlpha
Pros: Powerful, fast, lots of RAM, fast RAM, quiet
Cons: Still epensive, can run hot, doesn't block second slot but you may want to.
Summary: Overall you can find these cards for 270 and above. They have 80% performence of the more powerful GTX, and while not even close to the 1900XT By ATI it also cost 3 times less.
It has a lot of super fast RAM (DDR3) and has been able to run any windows theme, game (CS, CS:CZ, BF2, WoW, etc.) without any studders. Many games with recommened setting will underestmate the card, max the settings yourself, it will run just as well. Also it can be run in SLI so you don't have to pay for the power before you need it.
My one grip is that the fan is pretty small (however very quiet) and having a card right below it could cause cooling issue.