Originally Posted by Artonox
The hx520 if you are on a single card. It is quiet and modular too. If you are going dual, the hx620 and above would suffice. I've been hearing that only the highest end systems would need 600W or more so you need to know which gpu you are using as it is one of the most watt-consuming component
I agree with the above, and the hx series are great psu's. 5 year warranty makes them an even more attractive choice too.
The vx series work pretty well too if you are looking to build a single gpu rig, the vx450 gives 33A on a single +12V rail, which is better than some 500W psu's