“Himbo,” according to Dictionary.com, is a slang word, usually derogatory, that refers to an attractive but empty-headed man—a male “bimbo.” While we aren’t making any claims about these actors’ intelligence, they certainly had some empty-headed roles in box-office hits before disappearing into the Hollywood abyss. From dreamy-eyed Josh Hartnett to abs of steel Superman Brandon Routh, a look at once-budding action stars now seen mostly in discount DVD bins and on cable TV.