Bearing a boyish face and a tall, solid physique, How I Met Your Mother star Jason Segel is the gold standard when it comes to casting a manchild. He’s flaunted that skill in Knocked Up, Forgetting Sarah Marshall and now in The Five-Year Engagement -- in theaters on April 27. And no matter how unnerving the portrayal, he manages to be lovable. "If you can find the line between sympathetic and creepy," Segel told Entertainment Weekly, "you have reached a very funny area." Not only as he charmed his way into the hearts of us here at iVillage -- he has our vote for sexiest man alive! -- but it also seems that he has wooed a new lady these days: Michelle Williams!