WowAce

XP and Reputation bars

vChat

rSelfCast

LDB Broker launcher for HealBot

Protractor

opens/closes all bags when at merchant (instead of only the backpack)

Provides information about the player's bodyguard.

Reminds you to Life Tap and Dark Pact

Denial2

Does a /who search of multiple dungeons.

Open those clams (and other containers)

CharScanner scans Basic Character Data, Talent Specifications, Equipment, PvE/PvP Achievements, PvE Boss Kill Statistics and ...

Percent

Tracks profession specific cooldowns and items across all your characters

Reslack

Vengeance module for Broker displays.

Allows you to create icons, which can be customized greatly by user's input. CiR is more than just the usual cooldown tracker.

Keeps track of honor, PvP statistics, BG Marks, and Arena points.

Augmented Virtual Reality. Draw and add markers in the 3d world.

Shows the minimum durability of equipped items on the stats frame.