Yeah, how about just stay away from fighting other stereotypes?
I actually liked KilledBySuicide's idea, about being against, maybe not necessarily politics, but the Man.
Businessmen are running rampant and trying to brainwash everyone into being super-organized. Rules are being set up for mosh pits, mohawks are being given a legal height limit. And it's not just the punk crowd either. The size and amount Bling is being regulated, the placement of pant-holes must comply with regulation, and, worst of all, it is illegal to play music so loud that the neighbors can hear it!
Someone's got to stop this madness, so Problematic Punky takes his stash of pyrotechnics and goes on a mission to save the music world! On his way he meets allies like Ridiculous Rappy, Glamourless Gothy, and Dexterous Deathy (And many more), as well as enemies like Bane Al, Bo Ring, and Mon Otto Ny.
(BTW, I thought emo was a subgroup of punk.)