My EVGA 8800GTS fits as well, naturally, but I had to remove the 3.5" HDD that was parallel to it - it's too long to allow that drive to fit in the drive cage, so now I'm down to 3 3.5" HDDs in the case, rather than 4 3.5" HDDs in the case.
So now I have 8800GTS/320, 4x500GB (one's mounted externally and hanging from the PC - ugly), 1x Hauppauge Dual Tuner, 1x5.25" DVD+-RW, and 4x1GB of RAM. For heat reasons I've removed 1 of the TV tuners, so now I can record 2 shows at once, rather than 3.
Makes you wonder why anyone buys larger power supplies, doesn't it?