WowAce

Announces interrupts in the chat

Simple and clean Death Knight displays

Highly-configurable shield / absorb tracker.

Shows class colors on player nameplates and names

Clean looking square minimap with many options.

Note + rep tracking for players, with guild data sharing.

Does a /who search of multiple dungeons.

Displays the time until the next battle and more.

Display who crossed the charges on Thaddius

Add item levels to Inventorian

An extra set of 11x3 buttons, integrated into the default action bar.

Embeddable chat throttling library with traffic shaping and priorities

VisualThemes

Shows learned recipes of all characters.

PreferredItems

Toggle Windowed Mode with click or keybind.

A module that lets you find out what today's dailies are without having to visit the quest givers.

Leveling guides for trade skill professions.

Fires events whenever a raid member "fails".

Helps you automate selling stuff