Im a member of the largest music torrent site on the web. Everyday they have a top 10 downloaded torrents, most of it being new cds and from bands I’ve never heard of so I just download a bunch of stuff go through it and figure out what I like. Since I became a member of that site 2–3 years ago my music collection has grown exponentially.
During Christmas they had a huge freeleech thing going on, I grabbed something around 84 gigs of music I’m a total audiophile :P
I’ll also find new music from Last.fm since it keeps track of what I listen to and suggests new music for me.
Edit: To answer the second part of your question in the details, thats a really hard question, I can’t say who my favorite band is, there are just so many great artists out there. I could at most give you top 5 from any given genre. I tend to be very diverse when it comes to music and will listen to just about everything, I think talented musicians can be found in every genre. They just don’t turn up very often in pop and almost never in modern country.