WowAce

ClosetGnome_Mount

Keeps track of time played and rested XP across your characters.

FuBar_uFriends

FuBar_AmmoFu

FuBar_ExperienceFu

TradeStop

This will keep track of how much you have paid per item in your inventory. Only one of (Auctionator, Auctioneer, AuctionLite,...

Scans your Equipment for cumulative item bonuses and sums them up.

Keeps track of current money and all your characters on one realm.

cgCrafty

FuBar_DuraTek

Aspect checker addon for Hunters.

GonffBar

Mutt (Macro Update Target Tool) provides slash-commands that can patch the predefined targets in your macros.

Death reports

Separate indicator for your HoTs with timer.

Gears skins for Masque.

Display the global cooldown around your cursor. (+ other stuff)

Shows your standings with the factions.

EnchantList