WowAce

OneBag is a replacement for the default game bags that combines all the bags into one frame.

Achievements

Marks the locations of Hallow's End candy buckets on the worldmap and minimap.

Provides access to all Portal and Teleport spells on right click of one button.

Tracks the Blood Shield for Death Knights.

Bulk mail sending made really easy

Point to quest POIs on your minimap

Item stat breakdown, analysis and comparison

Libra

Displays the locations of Lunar Festival elders.

Addon to manipulate the map

One large inventory.

Timers for Buffs, DOTs, CC effects, etc..

Show buffs on nameplates.

an embeddable library providing an abstraction layer for tracking and querying Blizzard's Nameplate frames with ease and effi...

LiteStep skins for Masque.

Collectinator is an addon which will scan your pets and mounts and provide information on how to obtain them.

Database of Diminishing return categories and general data

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

Max Camera