Voyage of the Dawn Treader: I saw three writers credited at the end, and it explained a lot. It's got its moments where it's really on, but it's also got moments of tremendously, unbelievably cliche dialogue (shit like a character fainting and somebody saying "Was it something I said?", or "Stop it, both of you! Don't you see what's happening?"). It also tries to graft a plot backbone onto what's essentially an episodic story, complete with pointlessly throwing a collection quest on top of a story that's already a damn collection quest. For the most part this doesn't help, though there's some rejiggering of the order where it works better: Eustace spends more of the story as a dragon than in the book, and the Island of Dreams is turned into the climax of the story, which mostly works except that it fucking cribs the summoning of the monster straight from Ghostbusters and then Eustace sword-fights glowy green gas.
Oh, and the glowy green gas just represents pure evil. Or temptation, or sin, or some generally abstract badness. It may be the least subtle Narnia movie yet (though, in fairness, the least subtle bit, Aslan's "I am known by another name in your world" speech, IS straight out of the book).
On the plus side, the kid who plays Eustace is perfect. Hammy as hell, but that's exactly what the character calls for. He scowls and he shouts and he tantrums and he really steals every scene he's in. Oh, and Simon Pegg replaces Eddie Izzard as the voice of Reepicheep.
All in all, pretty meh and kind of a mess, but there are bits that work pretty well. Don't know if we'll see any more after this (though [spoiler]Jill Pole gets a namedrop[/spoiler] at the end), but Silver Chair is a much more straightforward story. Hell, the two after that are, too.