WowAce

Status indicator that shows the remaining of value of Powerword shield.

Automatically leaves the global channels when inside an instance/raid and restores them when exited.

TradeBar

Manager for DKP points. Requires DKP - Bidder as main Graphic User Interface.

Allows frames to be dragged around, without permanently changing their position.

Clean looking square minimap with many options.

Calculates optimal reforging for given weights/caps.

Warns you with sounds when you gain different shaman spells.

Omniscience

Hitman

Open all your mail

Allows customisation of login/logout system messages.

Combat log replacement

Toolset for tanks, providing information on taunts and other valuable information.

Cartographer_Mailboxes

A loot distribution addon meant to improve master looting during raids.

FuBar_HonorFu

Shows skills in a tooltip and allow them to be used. Also keeps track of Cooldowns.

Show coordinates on minimap

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