Read
this audio card roundup from the Tech Report. They usually have good reviews. The author includes his own subjective remarks regarding sound quality, which some people might not like, but I personally think it's better that not having any opinions.
The roundup includes two Hercules sound cards, the Turtle Beach Santa Cruz, the Philips Acoustic Edge, the SB Live! and the SB Audigy. Pretty good selection.
If you're too lazy to read the article, it basically says that the Audigy is by far the best for sound quality (music) and the Acoustic Edge for 3D sound (in games etc). But it's a good read, I very highly recommend it.