WowAce

Configurable Castbars

Babble-2.2

GrindStatus

Checks your gear before bosses and yells at you if you're an idiot

Quest History tracker and shows lists of quests in each category

Keeps track of HoTs, DoTs, Buffs and Cooldowns. With audio and text alerts to refresh them.

Remember locations that city guards direct you to for HandyNotes

Manufac

XRS

CandyBar style cooldown display

Track all threat redirection ability transfers and cooldowns (Misdirection and Tricks of the Trade).

Automatically enables or disables combat logging based on location.

Regain that wasted space!

Plugs classical world style fonts into LibSharedMedia-3.0

Automated smart raid marking to speed up trash clearing in instance runs

Smooth combat HUD based on ArcHUD2

Provides access to all Portal and Teleport spells on right click of one button.

Bayi's Extended Questlog

Configure triggers to send messages to your raid team such as timers, rotations, and health/power based triggers. Raid smarter not harder.

Try on different gear and see their total stats and their differences. In short, an ingame CT-Profiles-like addon.