It's not rock, but I just really love this song. Rebecca Sugar, the amazing composer of most of the songs you hear on Adventure Time, said that this was her last song for the series. (silently weeping on my keyboard right now.) This song is from the special "Fionna & Cake" episode in the latest season, where all the characters in the show appear as fictional, gender-swapped versions of themselves. Marshall Lee is the male counterpart of everyone's favorite vampire, Marceline, and his voice actor Donald Glover might be the winner of the world's-sexiest-voice competition.
No seriously, his voice turns me on. I would do naughty things to it and/or with it.