While at work, I listen to KPIG from Santa Cruz, CA (
www.kpig.com). They play a great mix of blues rock and folk, a genre that has come to be called "Americana" and features mostly singer/songwriters, acoustic guitars - sort of an alternative folk.
(reading back over that last paragraph I'm reminded of how silly it is to try to categorize music into some sort of neat pigeonhole).
I could listen to Tom Waits pretty much constantly, but then I couldn't listen to Neil Young, or Dylan.
On the other hand, I'm listening to an old John Coltrane album (Giant Steps) as I type this, with Charlie Mingus on deck. Just can't beat jazz first thing in the morning...
c~