A non-exhaustive list of Minecraft mods I really like
The gold standard of modern modded Minecraft shenanigans, with it's smooth animations, and crazy moving contraptions, and focus on automation/factories, and trains (if you're into that).
Easily one of the best magic systems I've seen in Minecraft, with research and potentially world ending threats. Also, the basis for the spectacular mod pack Blightfall, were all the weird corruption stuff is recontextualized as an alien taint already spread across the planet.
If Cookie Clicker was a Minecraft mod, it would be this. Converting any item into any other item thru a points system, with really powerful items to mold and shape your world to how you want.
Pocket dimensions for your building, and pocket dungeons for your exploring. Really cool if you're more into building interior spaces without having to plan how it will look on the outside.
Basically a requirement in every mod pack because of the recipe list. It would be a crime not to mention it.
It's really a shame I could never put a mod pack with all of these in it together since they're pretty much restricted to different versions of the game.