Yes. My "standard" PSU is the Corsair 550VX. It will power a system with any CPU and any single GPU video card.
OTOH, all the PSU calculators seem to overestimate PC power consumption. My gaming/media system has an OC'd Q9550, 4 GB or RAM, a GTX260, 3 HD's totaling 2.6 TB's, and a Soundblaster card. Doing my best to maximize the load (3 instances of Prime95 and one of 3DMark06), my Kill-a-Watt meter indicates that the system pulls 375 watts from the wall. At 80% efficiency, that's 300 watts from the PSU.
They key here is to select a good PSU.