WowAce

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

Checklist and notes addon.

ShammySpy

Makes grid QuickHealth aware

Send Mail to Groups

DynRepBar

Show an in combat indicator

Reverse Engineering will drill down and search your tradeskills for their elements

UnitActionBars2

A raid buff tracker

FuBar_ReloadUI

Target assistance by automatic rewriting of macros

Client for MagicDKP which handles standby calls and bidding on items.

SurgeonGeneral Listen CLient

Spell interrupt aid and announcement addon.

Reports the total threat on a mob at the end of combat.

A death track window for Recount

LDB display for Oak Interrupts Broker

Adds four icon indicators to Grid (top, bottom, left and right).

Displays online friends.