That link is a chart of cards you can compare by checking the box next to the cards you want to compare and clicking the compare button at the top or bottom of the page. I just recently got a GTX 260 for $187 but haven't been able to use it yet because I now need a new power supply (hinting my post in the graphics card section) but I've heard great things about it.
You will probably here a lot of debate about it elsewhere but those are just people that are glued to one side (nvidia vs. radeon.. boohoo) but if you look at a lot of reviews for the radeon you will see a lot of bad feedback.
Go check out Newegg.com for both the cards you want and look at the customer reviews, that gave me a good idea on which to choose.
If you choose the GTX 260 it's then going to be all about finding a good price, good luck.
p.s. of your going to go Radeon then check out the 4890 or the 4870.. compare those benchmarks to the GTX 260, strong points on both hard to choose from.