I will second Godspeed You! Black Emperor and Explosions in the Sky from Gooey, and also Moonsorrow because they are great.

Lykathea Aflame are a good band, too. Enslaved are valid, probably my favourite metal band at the moment. Sigh are also great, they do not constrict themselves to genre at all, and experiment in their songs almost on a whim.

Nick Drake is fantastic folk/acoustic guitar music from the seventies. His last album, Pink Moon, is amazing, and one of the best emotive pieces of music I've ever heard, and pretty much pisses on every band out there today trying to claim that they have "demons" that they let out in their music. Utter pap.

Dälek and Early DJ Shadow, (like, Endtroducing..... and The Private Press) are both extremely valid examples of how great hip hop can be when the people making the music don't stick to the conventions and actually PUSH BOUNDARIES and try different things. Endtroducing..... had some of the most atmospheric and beautiful musical soundscapes that I've ever heard in my life. Building Steam with a Grain of Salt still brings the hairs on my neck up.

Then you have Dälek, which sounds like the result you'd get if you took Godspeed You! Black Emperors darkest soundscape moments, put a heavy industrial slant on that and then mixed in a beat and an Emcee. I've never heard anything else like it in my life, it's great.