I haven't nominated something in a while, so... here it goes.
Phonography (1976) by R. Stevie Moore
I've recently discovered this guy's music, and I have to say that it's pretty interesting. Essentially, this is an early lo-fi album by a talented outsider musician who held a lot of influence in the creation of indie rock. It has psychedelia, experimentation, electronics, samples, weird vocals, etc. It's extremely unique, and there really wasn't much music like it at the time. I guess you could say that this album was an early stage in the evolution of indie and alternative rock.