WowAce

Simple display and management of Away / AFK / Busy / DND status via broker or minimap

Fancy up the ExtraActionButton frame

Angry Raid Points Client

Mapster's Minimap brother

Improved Quest Tracker

Omnibus

Constructs a SimC export string for an item without equipping it

Automatically and immediately cancels all in-game cinematics and movies

SurgeonGeneral

Embeddable chat throttling library with traffic shaping and priorities

Customizing your buff display

CombatLog in SimpleCombatlog style

Cartographer_QuestObjectives

Inventory and bank organizer.

Announces interrupts in the chat

Pet Theory

A collection of useful (guild management) tools and utilities for smarter than average bears.

AutoMagicly clicks though Daily Quests, and Turns them In.

LDB display of currencies, gold totals and session / daily / weekly statistics for all characters on a server.

Raid Cooldowns