Gleeb's Big Adventure is a Vanilla+, Create-heavy pack built on Forge!
Gleeb is a small grey alien who loves to explore. This pack creates an adventure that he would love, with more biomes with both Terralith and Oh The Biomes You'll Go, new structures added through YUNG's suite of mods, Structory, and When Dungeons Arise, and a number of new dimensions to explore with The Bumblezone, The Twilight Forest and Blue Skies!
There's a focus on physical machine-based tech through Create, and given interoperability with other mods with the use of add-on mods like Create: Crafts and Additions and Create: Enchantment Industry.
There are also many creatures to discover, added through mods like Alex's Mobs and Cobblemon. You won't ever be out of things to automate, as the mods Farmer's Delight, the Let's Do Bakery and Vinery series and Croptopia all provide different farmable and creatable goodies. This is just a small subset of what the modpack contains, there's even more in there for you to create and explore to your hearts content.
Ultimately this modpack was created so that I can have a good time with my friends, and if you can do that to, that rocks! 
Technical Specs
I strongly suggest using 6-8 GB of ram with this modpack. Though you could go as low as 4 if playing on a server. It's up to you really! Probably go 8 though!
YOU SHOULD DISABLE THE doCreeperDropsPlushBoxes GAMERULE
IT WILL CRASH THE GAME IF A CREEPER DIES AND TRIES TO SPAWN A BOX, THERE IS NO CONFIG OPTION FOR THIS LOL
/gamerule doCreeperDropsPlushBoxes false
There's a custom title screen thanks to Fancymenu, but if it's not your jam feel free to disable it with CTRL + ALT + C and disabling customizations. It's only the main menu that is effected.
Modlist
This mod adds another use for copper in the form of a copper carrot, like a golden carrot, but worse!
This mod adds another use for copper in the form of a copper carrot, like a golden carrot, but worse!