WowAce

GotWood

A lightweight addon that does something.

Displays classes and specialisation dependent stat priorities provided by icy-veins.com

Tells you which blob to kill at the Yor'sahj encounter in Dragon Soul.

GrindStatus

PT3Browser

Loudmouth

Toggles WoW to the forground on events.

Talented_Data

Various libraries based on LCD4Linux, offering users lower-level UI customizations.

Tracks interrupts

Adds a button to your character and inspect window that shows a summary of gear enchants and gems.

Tools for MultiBoxers or Group questing/leveling

VersionChecker

quick quest turnin and acceptance with a shared keybind

FuBar_VampwatchFu

Displays friend notes in unit tooltips, at logon, and in /who results.

FuBar_MicroMenuFu

Disease Tracker for Death Knights.

Tracks the precise arrival & departure schedules of boats and Zeppelins around Azeroth and displays them on the Mini-Map and ...