O’Dowd, playing down his cheekiness, is better than he’s been in any movie since “Bridesmaids.” Hawke, just when you think you’ve got him pegged, keeps finding new flavors [sic] of disillusioned charisma. And Byrne, who has the trickiest role in the movie (she has to walk around wearing a pout of dissatisfaction), keeps us on her side by investing Annie with that most indelible of qualities: the innocence that lives on the other side of heartbreak. “Juliet, Naked” is a feel-good movie for the best of reasons. It leaves you completely happy you met the people in it.