WowAce

Reno is a slash-command that can patch predefined options in a macro to change which abilities will be chosen.

RaidSpy

Raid loot tracking and text generation

RaidInfo

adds navigation buttons to Encounter Journal

New/Old BG indicator, Join by ID, Quick Leave Queue, etc.

LDB data source for currency flow

Loot management tool

Cryolysis 2

Adds party/raid role icons in useful places

Detects specific CDs and spellcasts

Auto and random summon highly customizable for your pets and mounts, with Data Broker support.

Insanity resource tracker for shadow priests.

A simplistic clock.

An addon to assist with organizing healing in a raid set up.

Add-on that shows in a unit tooltip window a number of killed mobs of the same kind

Auto roll greed, need, pass or manually roll on items.

Pins on the World Map for quests you have not completed yet

First Aid data for Ackis Recipe List.

An auction house AddOn to make the life of each fence easier.