I got my PS3 controller working over USB...but the process is kind of annoying, so I wouldn't really recommend it.
Main problem is likely that with 64-bit you need signed drivers unless you F8 at boot and tell the system to ignore that requirement...every...single...time...
(or you sign the drivers...)
You have to put the OS into test mode for that to work, and then you get a watermark in the corner of the screen that says "TEST MODE" which will annoy the hell out of you as if your desktop is shining a laser beam directly into your eyeballs.
You can remove that but it involves hacking Windows and MS might do something in an update in the future which might make Windows explode if you have done this.
The bootable USB stick method is the most convenient way IMO. Just stick it into one of your rear USB ports and forget about it. Edited, Apr 12th 2010 6:23pm by Lobivopis