2018 is still young but here's my list anyway:
1. Deadpool 2 (2018)
2. Bohemian Rhapsody (2018)
3. A Quiet Place (2018)
4. Hereditary (2018)
5. Game Night (2018)
6. Upgrade (2018)
7. Annihilation (2018)
8. A Simple Favor (2018)
9. Overlord (2018)
10. Suspiria (2018)
11. Summer of 84 (2018)
12. Halloween (2018)
13. Mandy (2018)
14. Unsane (2018)
15. Incident in a Ghostland (2018)
16. Jurassic World: Fallen Kingdom (2018)
17. Unfriended: Dark Web (2018)
18. Insidious: The Last Key (2018)
19. The Meg (2018)
20. Hell Fest (2018)
Bonus: Favorite 2018 bad movies
1. The Nun (2018)
2. The Predator (2018)
3. The First Purge (2018)
4. The Strangers: Prey at Night (2018)
5. The Possession of Hannah Grace (2018)
6. Deep Blue Sea 2 (2018)
7. The Axiom (2018)
I've only seen two from that list:
Bohemian Rhapsody, and Jurassic World: Fallen Kingdom. They were each OK.
in no real order
Avengers: Infinity War
Ready Player One
BlacKkKlansman
Black Panther
A Quiet Place
Bohemian Rhapsody
Ant-Man and the Wasp
Ocean's 8
Bad Times at the El Royale
Deadpool 2
Hereditary
Solo: A Star Wars Story
Skyscraper