Alloy (http://www.alloy.com)

Packed with content, Alloy could keep some teens entertained for hours with its interactive elements and endless stream of celebrity gossip and fashion features. That said, it's a pretty shallow site that's sometimes too snarky for its own good. "Oh No She Didn't!" rips on unsuspecting strangers who've allegedly committed crimes of fashion and encourages readers to weigh in on a scale from "eww" to "of course." The entertainment features -- including interviews with both A-listers and up-and-coming artists -- are a better option.