Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
The DX4's. I think they're pretty good for the money and fuss-free.

That's it. Though I've also heard that the DX4's might be lacking a bit if your into movies or games. There's an M-Audio LX 2.1 system that's probably better for that sort of thing (well, movies at least).
 
It's not a 'giant fart in bath' rumbler if that's what you mean. It's got a pretty decent range for a cheap speaker, and has less of a 'disconnect' in the sound range than many 2.1 systems.
 
Second hand Bang & Olufsen. Nobody fills a room like them (despite what some people think about them being overpriced). I got my first B&O system for christmas and don't intend on making it my last.

Check out www.lifestyle-av.co.uk. I bought my CD player from them, great service!
 
I recently replaced my creature2's with bose companion 3s and they do not disappoint. they will not only fill a room but also blow some walls down. I also recommend spending $20 and getting SRSiWow plugin for itunes.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.