WowAce

Customize the appearance of the chat bubbles.

Enables cooldown notification between players and allows party members access to each-others spell books.

Control screenshot format and quality via FuBar

Flames anyone who lets his debuff expire on Malygos Phase 3

Simple, nice-looking power bar addon for all classes.

"Shows Call To Arms status in an LDB data provider."

Denial2

WFtotem

LDB display for Oak Interrupts Broker

Helps you see the Halion's Corporeality during phase 3

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

Lets you drag UI frames around

Records mail when visiting the mailbox to make keeping track of mail and expiration dates easy.

Shows a countdown bar for the duration of auras (e.g. HoTs, DoTs)

ERP

Advanced Chat Filtering and Spam Blocking Addon

WhisperBid

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

Allows custom-triggered boss mod timers to be created

Tracks Black Market Auction House auctions.