Actually, I would recommend a soundcard, since the sampling rates on MOBO integrated sound are crap, and it is 16bit. I would go with the Sound Blaster Audigy2 ZS card, it is very good, and GREATLY increases sound quality. They run about 81-86 USD, so they are not SUPER expensive. Also, here are the speakers I would go with on a budget, they are very good (Cousin uses some we got him for Christmas)
They are not the best in the world, but on a budget, you would spend less then $150 for both the ZS and the speakers, and that would be one kick @ss setup for Music and games!!!