WowAce

Bind spells, items, and macros to keys, without using action buttons

Better quest log and tracker

FuBar_RecZone

Marks the locations of Hallow's End candy buckets on the worldmap and minimap.

Keeps track of durability and pops up a dialog to repair when you go to a vendor who can.

Shows where the equipment of inspected users or yourself is from.

An auction house AddOn to make the life of each fence easier.

Some handy events that should exist in the default UI

Cartographer_Routes

Tells you if you're buffed

A lightweight addon that does something.

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

A library to provide a clean dropdown menu interface.

ItemBonusLib

Point to quest POIs on your minimap

Combination of Titan LootType and Roll - stripped down and cleaned up.

Addon to provide a much nicer map

Tracks SendAddonMessage Spam

TabletLib

YssGuildShop