I've got all four in various places. On the desktop, I'm more or less stuck with nVidia simply because I don't want to buy new waterblocks, but otherwise it's just whatever gives me the best performance. Though at this point I'm migrating away from PCs as a whole (woot for Mac, and even more woot for Parallels), so I don't have a whole lot of say in the matter unless they do something unexpected with OSX (maybe when OS11 comes out they'll sell some semi-supported any hardware version of OSX...*crosses fingers*) Desktop is AMD/nVidia, as it was the best bang for the buck at the time. I was a fanboy to some extent for a while (actually, I used to be a hardcore ati fanboy) but at this point, I'll go for whoever offers me the best value and stop there.
