Loria (alpha)
siegment

Survival in hardcore acid-alien sci-fi themed world

Water Life
Gundul

new mobs for your river and sea water

Base Modpack
karlexceed

This combines several other mods that I consider a basic minimum starting point for worlds.

Draconis
ElCeejo

Adds advanced Dragons and powerful equipment.

Caverealms Lite
Shara

A mod for Minetest to add underground realms.