I actually plan to do a review of all major soundcards once I get around to finishing my audio guide. [One section to go!]. But as a general rule, at a given price:
ASUS > Auzentech = HT Omega > Creative
The ASUS Xonar DS is my lowest level recommendation of a entry level soundcard for non-headphone use. [For headphone users, I recommend the DG over the DS]. The slightly more expensive ASUS Xonar D1/DX is a better all around package, but costs almost twice as much. Even so, the DS is a very capable option as a cheap upgrade for users with a mid-end audio setup.