WowAce

Buffalo

ShadowGreenLight helps you decide if recasting SWP/Corruption is worthwhile

Assistance for the Ra-den encounter. (Unstable Vita order, ball kill order)

EUF is an enhance of wow original unit frames, provides hp with both value and %, and optional 3D portrait. Simple and Useful.

Raid Cooldowns

oUF element for highlighting debuffs that are dispellable by the player

FuBar_CheckStoneFu

A frame designed for each specialization of druid's watching their main power and important buffs/debuffs

Tells you if you're buffed

Buffalo2

Disease Tracker for Death Knights.

Warns you with sounds when you gain different shaman spells.

Information display for Hunters.

NBuffBars

Provides training reminders to help decipher the Blizzard Spell Alerts.

rSelfCast

Test whether the player can really dispell a buff or debuff, given its talents.

Detox

MoBuffs

Adds Buff/Debuff icons to the grid frame.