In your situation i recommend the SB Audigy 2ZS. It is the card I currently have, I stand behind it 100%. It is cheap, for what you are receiving, as it is loaded with features (THX cert, EAX, etc.) Look at it like this, you can purchase this card, which will last you a long time, and eventually pickup some speakers to match and utilize the THX certification. I personally have the Cambridge Soundworks THX 550 to compliment this card and it produces phenominal sound. Before I bought these speakers I had a set of $80 Creative 5.1 (prolly the same as you) running on this card and the difference between those cheap spkrs and the THX cert spkrs was incredible. If budget is a big issue, just take one thing at a time but dont waste your money investing in a good sound card if you dont plan on buying good spkrs as well.