Definitely add some Nick Drake to your collection. He made some cool music in the late 60s/early 70s. Check out "Day is Done" off of Five Leaves Left or "Pink Moon" off of... well, Pink Moon.
For some more recent music, you might wanna check out Iron & Wine. They do a pretty cool acoustic version of The Postal Service's "Such Great Heights" on the Garden State OST.
Also, Elliot Smith has made some great music. If you've seen Good Will Hunting, you might recognize "Miss Misery" - it was nominated for an Academy Award, methinks. ...and I think just about everything off of X/O is really good.
And even though you don't like country, have you checked out Johnny Cash's American Recordings series of CDs? I don't like country, but I really dug that collection. Check out any of the covers he's done (NIN's "Hurt", Depeche Mode's "Personal Jesus", Tom Petty's "I Won't Back Down", Soundgarden's "Rusty Cage", Will Oldham's "I See a Darkness")... they're all fantastic.