WowAce

OneView

Simple, light-weight, LDB-enabled timer that tracks how long you spend in combat

CombatAnnounce

Checklist and notes addon.

LibDataBroker plugin showing some random XP related data

Records mail when visiting the mailbox to make keeping track of mail and expiration dates easy.

A Perl layout with oUF.

Langoustine

Raid target control and instance shortcuts for Broker

For Developers (of Addons which uses LibWho-2.0): show queues and queries in realtime

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

BigWigs_HealbotAssist

OneChoice tries to help you reduce quest reward choices down to, ideally, one choice.

"Your quest log is full". How many quests do you have in your log?

Ignore more than 49 people, autoshared between your alts

Spyglass

Swap a random tabard every time you visit the bank if you are wearing one

PlayerNotes

Displays a grid of guild ranks versus permissions.

Helps to track outgoing mails