It depends. What are your system specs? How much gaming do you do, and what types of games (some require more horsepower than others). The main thing to think about right now is your future plans. DX10 cards will be out in 4-6 months and if you want to be the first on your block to have one, you shouldn't buy a top shelf card now. Although you can always sell it later and recoup some value, it may be better to just get a mid range card now. But to answer your question, in general the 7900GT is plenty strong, but the GX2 will last quite a while- as long as you don't feel the need to upgrade to DX10 right away. Or money isn't an issue.