This festival gives me the same vibe as Lollapalooza. That being said I'd like to see Phish, MIA, Dead Mau5, Gogol Bordello, The Black Keys, Slightly Stoopid, Gaslight Anthem, Lucero, Cage the Elephant, Frank Turner, and The Verve Pipe.
ACL and Lollapalooza are both owned/ran by the same company. I'd recommed making sure to see a rock show of The Verve Pipe. I know that they are playing the kids stage at ACL and Lolla this year. if you dont have young children, it may not be your Cup of Tea.