Well to echo what people here have said:
GC: Wavebird - no rumble, but solid construction and design... just make sure to turn it off when you are done, I've forgotten a couple times and drained the batteries.
XB: Logitech Cordless Precision - smaller (and cheaper) than the Cordless Controller, more like the XB Type S.
PS2: Logitech Cordless Action - again, smaller and cheaper than the previous version, $30 on Amazon. Has a useful auto-off when not being used, and supports rumble.
If you wanna be sneaky, grab the PS2 Cordless Action Controller. Then buy a XB/GC/PC to PS2 controller converters, put them together and you're set! It's the best gamepad possible for your PC. It maps nicely to the GC controls, and you'll have rumble, which the Wavebird doesn't.