Underappreciated known musicians:
Tom Waits
Skip James
Robert Johnson
Jelly Roll Morton (his solo-act, not big band music)
Little-known/independent bands:
The Weepies
www.myspace.com/theweepies - "World Spins Madly On"
Kelly Joe Phelps M. Ward
Coco Rosie
The Lemonheads/Evan Dando
Cat Power
Devendra BanhartJon Brion - Eternal Sunshine of the Spotless Mind, Punch Drunk Love, I <3 Huckabees composer
The Stills - I hate that these guys came out when they did, just one year too early for the disco rock stuff (The Killers, Keane, Snow Patrol, Franz Ferdinand, etc.) was popular. Stills > them.
Okkervil River - "The Latest Toughs"
Feist - "Mushaboom"
The Fiery Furnaces - "Here Comes the Summer"
Beachwood Sparks
The Thrills - "Saturday Night," "One Horse Town"
Ambulance, Ltd. - "Anecdote," "Ophelia," "Sugar Pill"
The WannadiesMy Morning Jacket
Yo La Tengo
There's probably enough filled space there for people to have stopped reading by now.
Please note that if I'm listening to music, it is in my CD player and not the radio. Sorry if you've heard of these people.
-hq