WowAce

A menu with useful searches for Inventorian

Helps you decide which ability to use next according to priority you set

A variant of AceGUI's Frame container with an editable input field

Target assistance by automatic rewriting of macros

Adds Friend and Guild options to the context menu of player units.

RaidHelper

Assistace for Blackhand (Mortar warning in P2, custom says for bombs and marks in P3)

Adds options to create customized layouts from within grid.

Bars showing amount of buffstacks

Adds indicators to the sides of Grid frames.

Retooled Professions

Options for TinyTip

Adds an Atlas button to FuBar.

Automatically switches Profiles of addons when changing spec

Remaining and rested XP Data Broker plugin.

AllYouCanEat shows information about the following statistics: beverages, foods, bandage types, potions, elixirs and flasks.

Swiss Army knife for instances, including player tracking, ignore buttons, loot tracking, notes, and more.

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

Cartographer_Trainers

Draws some lovely 3D portraits in the standard Blizzard artwork.