Scraps
Goops

Allows to recycle metal tools

Metatool
SX

Provides API to register node metadata tools along with few useful tools

Obdy
Sires

Adds some pretty OP tools :)

Darks
_Xenon

Adds dark stuff

Brights
_Xenon

Adds bright stuff

Floof
Momo

Add BicBiomeCraft inspired biomes, tools, and items.

Unified Hammers
Linuxdirk

Various hammers that can be used to crush nodes.

Banshee
ElCeejo

Adds Banshees, a ghostly mob that haunts pine forests

Portal gun
AiTechEye

Portals and stuff

faction items
GigaByte

add some items to be used as prizes for special events or player achievements

Lakemaker Mod
sunnysideup

A TNT block that makes lakes/bodies of water.

Silver
Jackknife

adds silver ore and tools

Stair Pick
BrandonReese

This is a specialized pick for making stairs.

Too many ores
TeufloV

This adds 53 new ores. But most of them are useless.