Not a band, but honestly, if you ask me this question, a year ago, I would have said Justin Timberlake. Since then, I guess I can say I'm more of a fan of his now. Nowadays, I say Taylor Swift. I heard her music at my house, from time to time, since my older sister has been playing her new album a good amount and, honestly, it's not that bad from what I've heard. It sounds very listenable compared to her contemporaries.
As for bands, hmmm, I guess Pearl Jam, Alice in Chains, Nirvana. Some of the songs, I hear, are good enough, but I just do not have as much personal enjoyment with those guys (I still appreciate what they contribute) as I do with Foo Fighters or Soundgarden.