Hmm, well, I don't really go to concerts much other than the symphony (I've only been to two -- the Killers and VAMPS). But I can definitely tell you who my favorite bands/singers are!
My favorite band of all time is L'Arc~en~Ciel -- a Japanese rock band. I love love love them. You can look them up on YouTube if you're curious.
As for more mainstream music, I just bought Owl City's album (the guy who sings the 10 million fireflies song?), which I love. I recently was introduced to a band called Elefant which I like a lot. I am also a huge fan of Muse (and I would totally go see them in concert if they came here!). Oh wait, I just looked at their tour dates and they are playing in November in Cincinnati -- that's only 2.5 hours away and my SIL lives there! Hmmm . . .
My music collection tends to the eclectic, with everything from Carrie Underwood to Ludacris. I usually have one or two songs from each of about a bazillion artists. If I hear something I like on the radio I will download it, but I don't usually buy whole albums. Probably the artists I have the most music by on my iPod other than the ones I mentioned above are Queen, Bon Jovi, some other Japanese bands, U2, and The Smashing Pumpkins (who I was really into in high school, but almost never listen to now).
Dagmar, you will laugh because you mentioned them on the chat thread, but I even have an album by the Partridge Family on my iPod!
I used to watch the show in reruns when I was a kid. Come on, get happy!