I only need stereo and my computer is hooked directly up to my home audio system. Some of the computer guys like the Logitech Z680s but they can't hold a candle to a decent stereo system in either sound quality or SPL, IMO.
I've ran klipsch pro media 2.1's in the past. Spendy, but I got the set for like $75 instead of the Best Buy price of $179.99. I liked them, sounded great, got mad loud.
I run the z680's, I think they are perfect for a relatively small room. The subs SQ is lacking, but it gets pretty loud to make up for it. For the price of a bit over 200 bucks, its really hard to put together a system that will sound better and do everything it does.
I was a big fan of my Cambridge soundworks Digital series... the 4.1 with sub... 150 cad is what i paid, doesn't get as loud as the logi's, bit more of a pain, but clear, oh so clear