WowAce

Ratings

Shows guild and system message of the day only if either one of them has changed since the last login.

Suppress chat messages when specified items are looted

Makes the Battle Objectives Frame movable

This addon helps with daily quests.

Show a bar indicating the unit's Burning Embers count.

Logs hunter's use of Feign Death

Adds cooldown timers to your trinket procs

Welfare Epics

Assistance for the Ra-den encounter. (Unstable Vita order, ball kill order)

PVPtimer

A collection management library similar to .NET's System.Linq

Tracks specialization and talent data for group members

FuBar_ReloadUI

ERP

Creates a broker plugin for all your broker launchers

Damnation

Shows a money overview for your current realm in the tooltip on the money in your bags

Never forget which one in that 5-mob pull casts what spell again.

Reverse Engineering will drill down and search your tradeskills for their elements