I'm using M-Audio's Delta 1010 LT soundcard with drivers made for Vista SP1, with Windows 7's compatibilty program and it works great.
This is a ten channel sound card, a little more than what most people would use, but I use it for music production.
I haven't tried it yet, but I'm guessing all the Delta series sound cards would work using the Vista SP1 drivers, I have the Delta 2496 Audiophile card but haven't tried it yet.