I'm putting together a new A64 San Diego system and wanted a video card recommendation (PCI-E). I'm willing to spend up to $400 on it, but I'm more concerned with maximizing bang for my buck than finding a $399 video card. I use my PC primarily for gaming, and I play CS:S at a very high level so I was thinking I should probably go ATI since they tend to outperform nVidia on Source engine games.