what sound card sholud i consider with my MSI mobo

I have an ASUS K7M with built in AC97 CODEC. I recently upgraded to SB Live 'OEM' for under 50 bucks. I also added another pair of speakers for a four speaker set-up. Honestly, if you are not super particular about your sound, you will be fine with the AC97. The reason I say this is, the biggest difference will be in midi sound and EAX enhanced games. 1.) Nearly every game made in the last few years uses redbook audio instead of midi. 2.) EAX is only impressive if you have the right speaker set-up and positioning (more money+pain in getting good separation). If you plan on plugging in an electronic keyboard and creating music though, you will have to upgrade to a PCI solution, the onboard audio CODEC is too slow for real time music synthesis.