Things to consider. What resolution will you run the games at? What is thew budget? What games will you be running? What is the cpu/mem/hdd in the current system, or soon to be system? What is the OS?
The reason I ask these is because the answers will help determine what card will be best to recommend. Most people have a 1440 x 900,1680 x 1050, 1920 x 1080 LCD display, but I have a non standard 2048 x 1152 display. So when I look at cards, and the test results at sites, I can tell that what a card does at 1920 x 1080 is a little better than I can expect to see the rest being equal. Budget is obvious, can't recommend a $300.00 card, if you only have $220.00 to spend. What types of games, the requirements for wow are vastly different than something like Skyrim with the HD pack. The best video card on the market is going to run like junk if the system only has 1 GB ram, and a 1 .6 Ghz single core cpu with a 8 year old IDE hdd @ 5400 RPM. The requirements for games run on windows 7 x 64 compared to windows xp x 32 are different, most games require 1.5 to 2 times the memory, and sometimes even a bump in speed, or a second core to run on the more demanding windows 7 x 64.