WowAce

Warns you with sounds when you gain different shaman spells.

LibDataBroker plugin showing some random XP related data

xchar

Warnings about tanking specific abilities

Display and change minimap tracking modes from your FuBar.

Restores channels and channel-window associations after disconnects remove them.

Manages the scanning of the auction house in a reliable an efficient manner.

PartyToGo

TGuildFrame

DogChow

Constructs a SimC export string for an item without equipping it

Shows where the equipment of inspected users or yourself is from.

ClosetGnome_Mount

Displays a grid of guild ranks versus permissions.

XP and Reputation bars

A helper addon for the achievements "Let It Snow", "Fistful of Love", "Shake Your Bunny-Maker", "Check Your Head", and "Turkey Lurkey"

Shows missing buffs and handles welfare and deluxe buffs as one (motw/gotw, blessings, etc.). This lets you see when you nee...

FuBar_FuzzyClockFu

Party and Raid roster library - one library for any group

Does a /who search of multiple dungeons.