Illinois is great, though I don't really count Sufjan as all that obscure anymore. "Casimir Pulaski Day" brings me to tears. Need to listen to the new stuff too...!
The California Guitar Trio is the most successful group to emerge from Guitar Craft and they've done some amazing stuff. Three acoustic guitarists playing in new standard tuning doing Pink Floyd, Bach, surf hits, originals, Guitar Craft repertoire and more. Amazing players.
Ed Harcourt is not particularly obscure, but I think he's the most well known here in Europe. A singer/songwriter with definite Tom Waits tendencies, only a bit rockier and not as carnivaly (and with a completely different voice, obviously...). Plays both guitar, piano and banjo. Many fine songs and someone I actually shook hands with once (complete with emabassing fanboy blithering of nonsense, oh yes).