Looking for fun mod(s) with friends!

Hey! I'm looking to start another yearly 2-week-long Minecraft server with some friends, and I'm looking for a mod (or multiple, even modpack, but not too technical) that is generally fun to play with friends. Example of what I like:

- I once played a mod which randomised everyone's gravity, which was fun (and nauseating).
- Tileman or Chunklocked type mods seem like a good time to me.
- Also saw a mod where the world border expands with every unique item you get. Seems fun, but perhaps a little too restricted in progression though.

Generally mods that add fun mechanics like that to the game. Really interested in what you like/recommend :)