Hey! I have been looking for songs about unrequited love for a male singer. I've found plenty for females, but the only ones I've found for men are from "Bare."
There is a RSO show called Mrs. Sharp (based loosely on the Pamela Smart case) that has a song in there called What I Wouldn't Do For You. http://www.youtube.com/watch?v=4TKooCzJe7o
This is exactly what you're looking for, heterosexual (no offense) unrequited love from a male perspective