Almost every single nForce and nForce2 motherboard on the planet use the same crappy audio chipset. You can get SB Live 5.1 cards these days for like $20 or less, and the sound quality should be markedly better.
There's no point in ruining an otherwise pretty decent gaming system by using onboard sound. Get at least an SBLive, if not an Audigy or Audigy 2.
I'm working in XP Pro, on an Athlon 2500+XP, an Nforce-factor board, not using the video, a BFG Gefore 6800OC Video card, and using the onboard sound.
Now, the odd thing is that every once in a while I start getting this intermittant thumping on the sound card. There's no sign as to where it's coming from but it's annoying as all hells. Ever heard of this happening before?