The 6600GT has DDR3, where the regular 6600 is plain DDR. Seen as how the 6600GPU really likes memory bandwidth, I’d go with the GT. The 6600 is a good card, and if you need to save money go for it. If you really wanted to go extreme cheap, they sell some 6200 cards that can be flashed with 6600 bioses! Then you’d get a helluva deal, but you need to do some research before you try that. The msi 6600 Diamond is the same as the 6600GT, it has ddr3, and can OC to gt levels. You can flash it with a GT bios, and it performs the same. If I were you , I’d get that card. Then there are other 6600 cards, like chaintech that are cheap, but pretty good. I’d get one of those if you have to save money, and don’t want to experiment with bios flashing. If you have the money, get a 6600GT, they’re really nice cards. One thing though, the new XFX cards have really crappy heatsinks on them, so aviod them! I saw you were thinking of one that has dual DVI, and XFX is the only one I know of that does that (my card is dual DVI). Leadtek, MSI, Chaintech, BFG, and gigabyte are the cards I’d use. If you can find them gainward are good too. There are some others, but those are the good ones that I’ve seen.