Depends on what you want. If you're happy with stereo, the onboard sound, on most motherboards, will be just fine. But if you want surround sound, for movies and games, you'll need more than standard onboard audio. There are cheap and expensive surround sound cards. The only one I have experience with is the Audigy 2 ZS Platinum. It costs a little over $200. Once you get a card for surround sound, you'll also need a set of 5.1 or 7.1 speakers, to hookup to the card. It can get kinda expensive.............
