I have a M2-ATX, I am using the 5 and 12 V outputs to power my monitor and a usb hub. On someone's advice here I ran the ground lines all the way to the monitor and hub, rather than using just the hot lines and a chassis ground. I ended up with a nasty ground loop though, and fixed it by grounding the negative of the usb hub to the chassis as well. So now I have basically the ground line coming out of the power supply grounded to the chassis as well.
Does this sound right? It makes sense to me, but are others doing that as well?