WowAce

An extra set of 11x3 buttons, integrated into the default action bar.

xchar

AnchorsAway

Adds easier gear switching to FuBar.

Converts incoming ALL CAPS CHAT into lowercase text.

Gives equipped and overall iLvl to indicate the quality of a character's gear.

This is an add-on to block incoming guild/party/duel requests (except for friends/party/guild) (previously ASSBlock)

View any characters bank and bags from anywhere. Stores items in Baggins submenu "Anywhere Bags."

SinkLib

Add lines to ore and gem tooltips that show prospecting sources/results.

Adds indicators to the sides of Grid frames.

Meeuuuh

fmBuffCheck

Embeddable library to track raid/party roster

Whats

Checklist and notes addon.

JasonQuest

Restores channels and channel-window associations after disconnects remove them.

An attempt at giving a complete overview of Arena battles

PetBar