WowAce

Adds Auctioneer "bought for" filters to Baggins ("disenchant", "vendor", etc)

LittleBlackBook

ClosetGnome_Zone

Color player names in chat by their corresponding raid class colors

Lightweight line-based info-display frame

Displays the internal cooldown of Eclipse as a ClassTimer bar

oUF_PowerSpark

Gives equipped and overall iLvl to indicate the quality of a character's gear.

Automatically retry teleporting to the instance when the server cannot create a new instance for you.

Customizable text display of character's power.

A very light weight UI plugin for Hermes

Adds a /rl command to reload the UI

sRaidFrames plugin - adds POH range indicators

Continously scan for addons using excessive CPU - especially bursts

Addon to manage WoW titles.

Displays how much your Shield Barrier will absorb if it is used at any given moment.

Shows the number of battle resurrections you have and when the next one will become available during a boss encounter.

Soundfile and Message Information for InstantSpells.

A small datatext for ElvUI that allows 1-click access to the GUI and bind interface

Wintergrasp Autoraid