WowAce

Co-ordinated targetless Party and Raid wipe recovery. Evolved

Kaliban's Class Loot List Star Display

Track all threat redirection ability transfers and cooldowns (Misdirection and Tricks of the Trade).

Tracks SendAddonMessage Spam

Keeps track of current money and all your characters on one realm.

DKP system for all guilds in the Banana Republic.

Dropdown library for Ace3 options, extensible to other options formats. Works ok.

ArcHUD2

Displays the locations of the chests for the Treasure, Treasure Everywhere achievement

A simple slash-command-based addon for querying item information from the Blizzard servers via ItemIDs and SpellIDs.

Show all the orbs for triggering Kosumoth

Displays Pet Info for Hunters and Warlocks. Also keeps track of Stables and Pet and Demon skills.

FuBar_TrainerFu

Load manager for AddOns

Says random things in chat when casting any spell or ability. Type "/ss help" for the user's manual.

Separate indicator for your HoTs with timer.

Plays sound when a ready check, LFG queue, battleground queue, or world battleground queue pops even if you have sounds turne...

A sexy logarithmic cooldown bar

Allows you to preview weapon glow in Dressing Room.

Some handy events that should exist in the default UI