WowAce

FuBar_ItemDBFu

Shows activity for hidden ChatFrames by making their tabs flash.

Add-on that shows which battle pets can be farmed this week

Loot Distribution System

Allows tradeskill usage by clicking items or reagents.

CraftList

LibRock-1.0

Shows the minimum durability of equipped items on the stats frame.

cyCircled

CombatLog in SimpleCombatlog style

Uses linear regression and a log of hitpoint values to estimate how long a boss has left to die and reach execute range.

Healer gear benchmark

FuBar_MicroMenuFu

Makes the message dialog movable

CCBreaker

oUF element for highlighting debuffs that are dispellable by the player

Gives a score for your kit allowing easy comparison with others, also colour codes kit based on appropriateness for your level.

Simple and clean Death Knight displays

MountUp

Stores a browsable database of spells that mobs cast