The non-spoiler overview: if you like Director Taika Waititi's sense of humour (try Hunt for the Wilderpeople) then you're going to love this. I laughed until I cried, constantly, for the whole film. Right from the start this film is given space to be funny, room for the jokes to breathe, and, when you get home and calm down a little, room for them to have layers. Thor: Ragnarok has a relatively straightforward plot. The cleverness comes in all of the little details, emotions, shout outs to previous Thor films and MCU films, to the comics and the myths, to character development and world building, and the jokes aren't seperate to that. They're funny because you know the history, or because the situation is hilarious, or because of the aciting and the facial expressions, and then you look again and there's more going on underneath. So much more. I'm still digging through them and I need to watch it again - hopefully this weekend. And then there's the themes. Which I can't spoil you for. But, oh my Thor, YES. Visually it's really colourful with some interesting choices, the music just works, everything is quote worthy, and everyone in the cast looks like they enjoyed the hell out of themselves making this film.
PS. I seem to know a lot of people who like Loki? Even though I live in the Assassins corner of the Internet? I blame @TricksyLiesmith. But apparently if you are a Loki and Thor fan this film is for you ;)
So where does this sit with the rest of the MCU? For me Winter Solider is the best in terms of plot. For humour Thor: Dark World and Gaurdians of the Galaxy. Then I just love all the ensemble films, especially for dialogue and banter, and I love Civil War. Thor: Ragnorak is easily the funniest film for me. The plot...Winter Solider still comes out top for me, for how timely and on point it was/is, how well it juggled everything, and the complete shake up of the MCU. Thor: Ragnarok shows how simple can be wonderful though, and shines in it's layers and themes. Beautiful layers and themes. After one viewing? Thor: Ragnarok is definitely the best Thor film and easily one of my favourites in the whole MCU.
Extras: look, we all know by now to stay until the end of a Marvel film, so pin your butt to that seat. There's a mid credits scene and an after credits scene. Oh, and there's some amazing cameos and who knows how many Easter eggs - I'm waiting for YOU so you can tell me what I've missed :D