Since billsfan89 hasn't come around to champion The Gaslight Anthem yet, I'll do it for him. All three albums are worth a listen; I really enjoy their second album, "The '59 Sound."
Band of Horses is one of my favorite "new" bands - they're great live, too.
I second The Black Keys.
For me, Guster is hit or miss, but I know some people really enjoy them.
Against Me! is a new-ish punk-ish band that I enjoy.
I also enjoy:
The National
The Ruse
The Soundtrack of our Lives
The Antlers
Beirut
The Cat Empire