There are spoilers ahead so proceed only if you are interested in reading such things.
For real. This is your warning.
We do not want to spoil the movie if you don’t want it spoiled.
Credit to JadeJaws
Sif dies when Hela destroys Asgard.
Hulk wins the fight against Thor kinda but not really.
Loki is now good again and him and Thor joke about him returning to Earth.
Surtur is resurrected by Thor and Loki to defeat Hela. The screen of Hulk jumping at Surtur is a ruse as Surtur is there to fight Hela not Thor and Hulk.
Movie is overly humorous and Korg looks to be a continuing character so worth to pick up his first appearance. As Korg Incredible Hulk #93
Asgard is destroyed completely.
Thor loses an eye.
Hela is Thor’s sister.
Two end credit scenes: Grandmaster playing the piano in one and the other Loki and Thor in a spaceship and they spot Thanos’s spaceship the Sanctuary in the distance.