Well, I'm running my Xtreme Gamer off of an old 2.1 Sony stereo that's at least two four years old, and I can't go back to onboard. After playing a few songs on the sound card, then switching to onboard, it was too muddy to stand.
I like use my cans sometimes too, though.
EDIT: In fact, the Xtreme Gamer is on sale for $70. If you got that, you'd still have enough money for a pair of HARX700's (You'd have to order from Buy.com or Amazon, though. Newegg doesn't have them). $103 for both.