They steal cars (and then have sex in them), deal drugs, start fistfights, and — gasp! — masturbate. The misfit teens of BBC America’s Skins (Sundays, 10 p.m.) may make the rich-kid rabble-rousers of Gossip Girl seem positively tame, but the show is more than mere shock value, sporting a wicked sense of humor as well as a surprising amount of heart (as a recent episode on anorexia proved). In fact, one could describe Skins as a randier version of Freaks and Geeks. With accents.