Legend of the Guardians: Well, there's nothing new under the sun; even the target audience of this movie has probably already seen all the straight-outta-Joseph Campbell elements of the story. But they're put together well, with a good cast (and no stunt casting to speak of -- I only recognize a couple of names in the cast, and they're serious fucking Shakespearean thespians), and some pretty gorgeous feather animation. And it's all played straight and doesn't talk down to the audience, with the exception of a few you've-heard-all-these-jokes-before comic relief moments and a godawful, totally-out-of-place teeny pop track in the middle of the movie for no goddamn reason. (My thought during that scene: "This shit is exactly the reason we didn't get a Bone movie 10 years ago.")
And it has a bit of metafictional fun with some of the tropes, too; the main character actually SPELLS OUT the loose ends left over for a sequel in a monologue at the end, and there's a bit of a nod to the fact that the prophesied horrible long trial-filled journey they have to take to Ga'Hoole actually only takes one scene.
All in all, I'd say it's forgettable simply because it's a textbook example of the genre, but it also happens to be a very well-assembled example. If you've got some kids to take to a movie for a few hours, you could do a damn sight worse.
Also there's a Wile E Coyote short at the beginning. It's not Chuck Jones quality, but that's an awfully high standard; it's perfectly satisfactory. I'd have preferred to see it done with cels, but it works just fine in CG.