WowAce

Mutes various chat related annoyances while in capital cities and instances.

Dynamic mount macro generator

Adds your name to chat messages

CT_RaidAssist style raid frames

Displays information about the current zone on the World Map

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

Barks at you when you target a crowd-controlled unit

ItemPriceTooltip

Utility library with shared functions and data for various addons by NeoTron.

Adds a highlight border to items in your MogIt Wishlist, making them easier to see.

Visualises healing.

FlexBar2

Checks your gear before bosses and yells at you if you're an idiot

Inspects all members of raid and saves in database, as well as lists people's dkp values

Provides a quick display for the LFG Call to Arms

Shows class colors on player nameplates and names

A library to help with localization of talent trees.

Display Garrison missons for all Characters

Show what quests have changed

Some handy events that should exist in the default UI