WowAce

Enables cooldown notification between players and allows party members access to each-others spell books.

Simple, nice-looking power bar addon for all classes.

Shows loot information in item tooltips

ERP

Assistance for the Ra-den encounter. (Unstable Vita order, ball kill order)

WhisperBid

Denial2

Allows movement and scaling of class-specific resource displays

Shows a countdown bar for the duration of auras (e.g. HoTs, DoTs)

Animated target indicator

Never forget which one in that 5-mob pull casts what spell again.

Tracks Black Market Auction House auctions.

Shows who controls Wintergrasp and the time until the next battle.

Improvements to the standard Blizzard Eclipse bar for balance druids. Use /ebp for the config screen.

SkadaScroll is a plug-in for Skada Damage Meter that provides additional options for scrolling the bar displays. It requires ...

Fancy up the PlayerPowerBarAlt frame

Collects and displays census information. This AddOn is licenced under the GNU GPL, see GPL.txt for details.

Small addon to copy chat lines.

Fancy up the ExtraActionButton frame

"Shows Call To Arms status in an LDB data provider."