SPOILER FREE PORTION:
Thor Ragnarok is that favorite, dogeared Marvel comic that you have from the late 1970s where your favorite heroes team up. It's silly, corny, and printed in four colors. The story doesn't make a lot of sense and they crammed a lot into 22 pages. But who cares. You were 15 when you read it, and not every comic has to be Watchmen. Just seeing the cover again makes you smile, and you can forgive plot holes, and bad dialog and poor character motivations because Thor teamed up with Hulk and Doctor Strange that's so freaking cool!
This movie only tries to be one thing: fun. And the film is fun. And funny. And big, colorful..
People are going to say this movie is a mess. So is a food-fight. Doesn't mean it's not awesome. Go see it.
SPOILERS FOLLOW: STOP READING UNTIL YOU'VE SEEN THOR RAGNAROK
My one gripe (and it didn't prevent me from having a good time): I hate Asgard.
I care about Thor and Loki and their relationship with their parents. But the rest of Asgard makes very little sense to me. It's all swords and shields but also laser guns and spaceships. Sure, Star Wars mixes fantasy and technology, but Asgard thorws gods, dragons, demons, and frost giants in there too. In the first movie Thor tells Jane that on Asgard science and magic are the same thing, but that's not true. They cast magic spells, and they fly spaceships with lasers. It's two different things and it doesn't make any sense at all.
When Thor chooses to let Ragnarok happen and destroy Asgard in order to defeat Hela, I was thrilled. I think it works better if Asgard is a people and not a place. Did anyone else notice how this movie went out of its way to point out that Asgard was all smoke and mirrors? How Odin was far from benevolent (and in the end his just kind of leaves his kids to clean up his messes). The warriors three are slain without so much as a tear being shed. And in a very fun continuity-clean-up punchine, we learn most of the stuff in Odin's vault is fake.
I also feel that maybe this was two differnet idea for Thor movies they just crammed together into one movie. Sakaar/Hulk-Thor buddy movie and Hela/Ragnarok movie. Whatever. It was fun the who way through regardless.
Previous Thor movies probably took themselves too seriously. Ragnarok probably didn't take itself seriously enough. At least this time they erred on the right side in my opinion.