egg_future

It's just a good modpack all around. Interesting and engaging story/scenario, great choice of mods, great quests. The limited space is challenging without being annoying or tedious.
Not necessarily an expert pack but it's so well made that it feels like one.

This is by far the most impressive total conversion modpack I've ever seen. The weapons, maps, sounds, effects, animations and movement are comparable to something made by an established game developer. It's great to jump in with friends but it's still fun to play solo during peak hours.
The biggest downside to this game is the lack of active players, and the disparity between new players and the veteran players.

It's a pack with general progression starting on a wasteland overworld where you have to build a rocket and travel to several planets to look for parts to upgrade your ship. Also Ratlantis.
It has a lot of gun mods but techguns is my favorite out of them. It also has Immersive Vehicles if you like roleplay or impractical, clunky transport (its fun to play with though). I also like rats and this pack implements it pretty well. A lot of my fun came from gathering a rat family and building a home for them, trying to get them to work with other mods (varied success), using them for combat, and anything else I could think of. There's also personal favorites like the portal gun and inventory pets that can only be found in airdrops, which is pretty cool.
Almost none of the recipes are configured so a lot of overpowered stuff is available at the start. There's barely any challenge after a certain point, so a lot of progression is merely searching dungeons on different planets to upgrade your rocket.
It's slightly specific, but if you like kitchen sink packs with guns and space, then this is a great choice.

A short but very fun modpack. You spawn in the overworld and have to travel to different structures and dimensions to find the 12 eyes from End Remastered. There are some base building and villager managing features but most of the fun comes from speeding through the different dimensions, grappling from building to building, blasting everything down and looting cool stuff to put on your gun.
There's lore and voice acting in the modpack too. It's mostly a humorous and childish type of humor which might not be for everyone but it adds a lot of personality to the game.
The pack is highly optimized. It's recommended to use optifine for some custom textures and other aesthetic things the dev recommended but the performance boost from rubidium is too good to pass up in my opinion. Runs great on my i5-6500. Mobs can spawn in large amounts sometimes which might affect tps.
The game has a couple bugs and unfinished parts, which is normal of a game still in development.

Overall, this is a one-time experience. There's really nothing else similar to Jetpack Cat. I rarely replay modpacks, but I replay this one a lot. It's just too much fun.