WowAce

Automatic ammo reloading and selection, with warnings.

Adds on-screen buttons for the farming tools and seeds.

A loot distribution addon meant to improve master looting during raids.

Adds a confirmation dialog when crafting Bind-On-Pickup trade skill items

Smooth combat HUD based on ArcHUD2

Provides the ability to suppress specific spellcasts like "Deaden" from your casting bars.

Allows you to create icons, which can be customized greatly by user's input. CiR is more than just the usual cooldown tracker.

LDB data source displaying character stats

Bars showing amount of buffstacks

Quest helping: fetching items to use, that sort of thing.

VendorSearch adds search features when buying items from any vendor

PreferredItems

Captures chatframe Tradeskill Links for later reference in an easy to read format

Crowd-control monitor

Sets you to DND when you fight a boss, and some other crap.

ItemEnchantApplication

Adds aura indicators to unit frames

Scorchio!

Communicates with guild members for their positions on the world map

StarVisuals displays various data visualizations