Who does everyone like to see live in terms of music? For me there are some traditionally great live acts, such as Springsteen who always puts on a good show... Same with Elton John. But newer stuff that's out there always makes for a more interesting show... Something about seeing an act while they're still fresh and early in their career is darn special.
If you ever get to see a group called The Go! Team playing, and you want to experience some AMAZING High-Energy music, you should definitely go!!! Also, Art Brut puts on a great live set. If Blues is your cup of tea, try to see Bill Perry (NOT the guy from the 80's rock band, Journey I think... he's a Blues guitarist). He puts on a Jimi Hendrix set that blows me away!
What's some other suggestions out there?