My current Addon Listing for World of Warcraft:

AtlasLoot Enhanced is an UI mod allowing for loot tables of bosses to be browsed whenever needed within the game. It can access full item tooltips, show drop rates, allow items to be chat linked and to use the dressing room.

Bagnon is an addon that merges all of your bags into three frames: One for your inventory, one for your bank, and one for your keyring.

Deadly Boss Mods
Boss mods for all raid bosses.

Dominos is an action bar addon/modifier.

Fishing Buddy
A fishing addon that keeps track of the fish you catch and helps manage your fishing gear.

LootHog detects and tracks rolls which are made with ‘/random’ or ‘/roll’ and sorts them, allowing raid leaders to announce roll winners quickly and easily.

RatingBuster started out as an addon that converts combat ratings in your tooltips into percentages, so that you have more meaningful information when comparing different items. The design aim of RatingBuster is to provide detailed, meaningful and customizable information about items so you can easily decide for yourself which item is better.

Recount is a graphical damage meter.

Make your minimap ubersexah!

OmniCC is an addon that adds text to items/spells/abilities that are on cooldown to indicate when they’ll be ready for use.

X-Perl UnitFrames
Perl, with Extra stuff. Much enhanced from Nymbia’s Perl UnitFrames, and a complete replacement for Blizzard’s default unit frames, including raid frames and raid tools, with little remaining of the original Nymbia code.

A remake of the built-in lootframe.

Raid/Party Specific Addons:

Grid is a modular, lightweight and screen-estate saving grid of party/raid unit frames based on Ace2 and various embedded libraries provided by the Ace-community.

Raid-frames like healing addon.

Omen is a threat meter.

For fun Addons:

After successfully bringing the Bejeweled experience into WoW, the PopCap Guild decided to tackle another of our favorite things: Peggle.  We wanted something more competitive that we could use to settle loot disputes and challenge each other while we waited for that last raid member to log on. We’ve packed in some great touches for the add-on version of Peggle, and now it’s ready to be shared with the world!

Lots of PopCap employees are also hardcore WoW players, who alt-tab during long flights or queues to kill time with Bejeweled. So when we learned we could actually implement Bejeweled inside WoW through an Add-On, we were intrigued.