What type of speakers should buy, and how much should I buy them for?

I am looking for some good speakers, that will connect to my computer, iPod, and TV. I prefer 5.1 speakers, but if there are some other speakers that sound just as good, then I might buy some of those. I love a lot of bass for movies and music, but I want the sound to be smooth. I listen to music very, VERY, loud so loudness is a big factor to me. My budget is 100 bucks or less, but I might be able to stretch to 120 dollars if necessary. They are going to be placed in a small bedroom that's sort of crowded with furniture, but not to the point where you cant walk or move around.