Adam Sandler may possibly be the most annoying celebrity on this list. In his movies he often plays the same dumb character — a goofball (usually who lisps). Check out his movie Jack and Jill for a doubly annoying dose of Sandler, playing a twin brother and sister. Did you happen to see his movie That's My Boy, in which the incredibly unfunny premise was about a 12-year-old kid who knocks up his teacher, then has to raise his child (who also finds him annoying and as soon as he's 18, moves away)? No, we didn't think so, considering it was his biggest box office flop to date — making back only half of its $70 million production cost.