I might as well chime in

!
Another Very Important factor is how efficient the PWS is. I'm a big fan of bigger is better (if you can afford it). For most single video card rigs a good 650W is fine unless you're running multiple HDDs in a RAID or some-such. I'm a fan of 2 HDDs--one for running OS and programs and one for backup. Currently, I like Antec and Corsair PWS's the most--best bang for the buck IMO.
@ mr chris: That Antec 1200 is a Great Case! I'm looking at getting the 900 version in the near future (big enough for what I build).