Best speakers for listening to music?

I listen to music in my room a lot and I thought it'd be nice to get a good speaker system, preferably under $100, but if it's really good, I'll consider over. I've been looking around online on amazon and youtube reviews and there's just So MANY options I have no idea which to get. Should I get one that's just a single speaker, or one with bluetooth speakers to put around my room sort of like surround sound? Which brands are reliable? I have an iPhone, so should I get one with a docking station? I listen to mostly rock and metal, so which specifications would I look for to get the best sound for that? I have no idea which one to get, what would you suggest and what tips do you have for me to help me pick out the right ones?

No docking stations or single systems please, if you want good quality.
First thing's first go to a thrift store and find a stereo receiver unit, should be anywhere from 20-35 dollars. If it's higher try to bargain with them.

You can also check for some speakers there you can find some real gems at thrift stores that will be loads better than one of those dock speakers

If you want some new good speakers for the money check out the ones monoprice puts out, they are cheap and will be great bang for the buck
here's a list of what they have, all in your price range, monoprice really cuts out the middleman and have actually been sued by Energy a subsidary of Klipsch (Pretty renowned brand of audio) for buying the same speakers from the same company and selling them

http://www.monoprice.com/Category?c_id=109&cp_id=10904&cs_id=1090407

That's what I'd get with that price, so thrift store receiver and pick from those speakers.
Oh and you'll need a 3.5mm to RCA cable as well,

http://www.monoprice.com/Product?c_id=102&cp_id=10218&cs_id=1021815&p_id=5597&seq=1&format=2