I bought a Creative X-Fi (THE XTREEEEEME SOUNDCARD) to replace the onboard audio on parabellum (which briefly replaced my old OEM SB Live). It was on sale at Amazon. Here is what I've noticed: I can use my headphones
and not hear PC noise, even with the volume cranked. Both the NForce4 and especially the SB Live were incredibly noisy.
And just as important, Oblivion is running much smoother. It used to jerk around some in town, but now it looks like I'm back to the GPU being the bottleneck ;) I had a feeling those REALTEK drivers were killing my performance.
So yeah, even though they are horrible litigious bastards, I stand by my brand loyalty for a gaming soundcard!
P.S. I haven't installed the cool front panel yet because I lost the drive rails, and have to wait for new ones to show up. It's much snazzier than my original SB Live front panel.
 Ultrasone HFI-650