Jared Leto. The dude's a pretty good musician AND a killer actor - check out what he did in Dallas Buyers Club. As soon as I heard about his role in that I became a fan.
I haven't really checked out a lot of his music (and what I have didn't stick with me), but Mr. Nobody is one of my favorite films of all time. He completely slays in that film.
Aside from that, I've always been a fan of Protest The Hero, but recently I feel like I've developed a deeper appreciation for their music and I like them more than ever before.