I agree with redwing. Also, check out this THG article:
http://www.tomshardware.com/2006/08/25/sub_200_pci_express_graphics_card_showdown/
If you plan to purchase a big-box retail computer, then you must consider power supply constraints. The 7600 GT is comparatively power efficient, so it doesn't require a molex connector. Of the 7600 GT cards available, the Gigabyte Silent Pipe 2 featured in the article is an excellent choice because it's a small card, and as such, will be the least obstructive to airflow within a snug OEM case. It also has a well designed cooling solution, overclocks nicely, and will perform well enough, at present, to fill the game gap on most any brand OEM system you decide to purchase.
If, conversely, you plan to purchse a build-to-order system, then your choices won't be so limited by power or architecture. In that event, the the X850 XT, (I've owned one and they're excellent), or the X1800 XT, (overclocked as described at the end of the article), might be a great choice for now. Remember that whatever graphics solution you choose, certain degrees of heat (no pun intended) will be produced during gaming.
When considering which card to purchase, try to select a solution that will benefit the entire system cooling scheme. Newer cards that are designed with overboard exaust are prefered to cards which "heat polute" the case, and merely recirculate their own heat. This becomes particularly problematic when considering the impact that prolonged excessive heat poses to other system components such as hard drives, or when trying to keep an overclocked CPU cool.
In electronics, we always tip the scale in favor of cool over quiet, and when meticulously designed, we achieve a cool balance. Whatever you decide upon, good luck with your new rig, and enjoy!