Last week, The Gaslight Anthem, one of my new favorite bands from 2008, was on Letterman. They performed their song "The '59 Sound", which, if you haven't heard, you need to check it out above. I would advise listening to the album version too, especially if you are not too impressed with their performance here (the album is better...).
The Gaslight Anthem are from Jersey, and uncoincidentally, sound like a punk rock version of The Boss, if they had Social Distortion, Against Me! and the Killers' bastard love child of rock playing their music and singing with Springsteen writing the lyrics.
I started with 2008's The '59 Sound, but those that I have talked to that have been a fan for a little while have told me to start with 2007's Sink or Swim and go from there. The Gaslight Anthem's The '59 Sound will be in the top of my list for '08, so keep an eye out for that.