WowAce

Enhances the default AddOns list.

In-game theorycraft. Calculates actual damage/healing based on gear, talents and buffs.

Bulk mail reception made really easy

Floating Combat Text of awesomeness. Caw. It'll eat your crackers.

Configurable Castbars

Entertaining kill-shot notification.

Create panels for customizing your UI, sucessor to eePanels

XP bar using Ace3.

Numerical and graphical display of Combo Points and similar buffs/debuffs. Also tracks Holy Power and Soul Shards.

Compact rune and proc display for Death Knights.

Library providing mappings between trade skill recipes, spells and created items

Database sharing module for GatherMate2

Minimap addon of awesomeness. *chewing sound*. It'll nibble your hay pellets.

Tracks the Blood Shield for Death Knights.

Database of Vendor locations for HandyNotes

Food/water macro generator

Attach diminishing return icons to unit frames.

Bulk mail sending made really easy

Displays the locations of Garrison music scrolls.

Addon to manipulate the map