Just stumbled upon a great music poster website called The Small Stakes . They have some of the best poster art I've ever seen in terms of miminalist, funky, modern designs that would look fantastic on a living room wall. And if you're at least a semi-middle class person their prices aren't even that bad (if you're a poor college student, it's a little rougher). I love these though and would consider forking over the $25 plus shipping fees for a few of them if I didn't then have to buy an additional frame, border, etc. to make it look right on my already carefully decorated walls.
But in all seriousness, these are exceptional..