Antec, makers of everything from computer cases to powersupplies, has hit a goldmine with the Quadro 850 Watt. Coming in at a standard ATX form factor, this power supply fits nicely in any case, though I recommend a larger case due to heat that is produced. This whisper quite power supply is on 24/7/365 in my room, so keeping noise minimal with this machine was almost as paramount as gaming quality.
While voltages where decently stable, the sheer excess of power more then makes up for it. Running a Core 2 Quad Q6700, 4GB of PNY667(at the time, now Corsair 800), 1.6 Terabytes of hard drive space including one 10k RPM Raptor Drive, 2 DVD-RW drives, and Ageia PhysX card, a Razer Barracuda Soundcard, and an nVidia 8800GT, this is a no holds barred power supply. There was no issue on overclocking, and with 850 Watts, there is room for future additions. With dual PCI Express 2.0 power connectors, and an 8 pin molex for CPU power in addition to the standard 4 pin, this power supply is ready for the future.