WowAce

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

Show all the orbs for triggering Kosumoth

Omnibus

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

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

Tracks SendAddonMessage Spam

Co-ordinated targetless Party and Raid wipe recovery. Evolved

ArcHUD2

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

Load manager for AddOns

A sexy logarithmic cooldown bar

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...

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

Allows you to preview weapon glow in Dressing Room.

DKP system for all guilds in the Banana Republic.

TomTom CrazyArrow pointing to the targeted group member

Deathknight Rune Display

Some handy events that should exist in the default UI

Show where the chests are for Withered Army Training