Sufjan Stevens. "Come On Feel The Illinoise!" is the 2nd album in his attempt to make an album about each of the 50 states, and if they get any better we'll be hailing him as the next dylan soon. Then again people hailed Conor Oberst and Fischerspooner as the "Next Dylan" also.
People alwyas forget about Curtis Mayfield (besides Superfly). Pick up some of his stuff, and his work with The Impressions is, well, impressive. Much of their stuff is politically charged, but that doesn't take away from his great voice. I'd say that "People Get Ready" is a good album to start with.
Iron & Wine is great, Sam Beam has a sweet voice for lack of a better adjective (and not sweet as in "Dude Where's My Car?" sweet, but sweet like honey). For me, "The Creek Drank The Cradle" is his best work, but you really can't go wrong with any of his LPs or EPs.
M Ward is a great indie musician in the vein of Iron & Wine and Sufjan Stevens. I only have one of his albums, but "Transistor Radio" is very good, I especially like the song "Hi-Fi".
And if you haven't listened to Tom Waits, shame on you. Do so now. My favorite song is "Way Down In The Hole" (also known as the theme to the best drama on TV, HBO's "The Wire"😉
EDIT: The link wasn't working, so if I already suggested anything you already have, you have my permission to beat me with a stick.