Bucket lite
daret

Bucket - fork of Minetest Game mod with reduced "bucket" liquid flowing

Loria (alpha)
siegment

Survival in hardcore acid-alien sci-fi themed world

NodeCore Adamant
Winter94

Adds Adamant, a new metal ore, deep underground/

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.

Whynot
bell07

Aims to get all existing high quality mods working together

Portal gun
AiTechEye

Portals and stuff

Caverealms Lite
Shara

A mod for Minetest to add underground realms.