If you payed alot of money for a sound card, save some money and get ones that plug into that and avoid USB.

If you have onboard sound, pay the extra and get a good set of USB headphones.

Either way, you will get good sound out of them as long as you don't buy the cheapest ones available. Plantronics makes some of the best headphones I have used for PC gaming, but they are mostly USB. I used to use a pair when I had onboard sound, now I have a nice creative soundcard, so I plan on buying a good jack based headset.