Tom Hiddleston and Chris Hemsworth in Thor: The Dark WorldTHOR: THE DARK WORLD

As the comic-book demigod Loki, the nefarious thorn-in-the-side to the Avengers and adopted brother to Thor, Tom Hiddleston, in the Marvel Studios movies, exudes a teasing, seductive malevolence. With his sharp, angular features and chilling gaze that suggests he might prefer eating you to killing you, he's a wonderfully unstable and hypnotic screen creation. Yet the brilliance in Hiddleston's interpretation is that his Loki is also so damned charming. The character may forever be planning destruction or plotting revenge - specifically against the golden-haired preferred son with the red cape and hammer - but Hiddleston's bearing is so smooth and relaxed, and his wide grin so infectious, that you almost can't help rooting for him, especially because he also, generally, gets his movies' best jokes.

Channing Tatum and Amanda Seyfried in Dear JohnDEAR JOHN

Since no one's been pressing a gun to my head, I haven't read Nicholas Sparks' Dear John, which concerns a pair of star-crossed lovers whose romance is derailed by the young man's Army tenure. I have, however, seen director Lasse Hallström's screen version, which apparently follows the novel's blueprint faithfully (albeit with an altered ending), so permit me a question: Does Sparks have absolutely no shame?