WowAce

Bars showing amount of buffstacks

Skip the gossip and select the normal NPC action

Provides training reminders to help decipher the Blizzard Spell Alerts.

Automatically and immediately cancels all in-game cinematics and movies

aUF_Banzai

Allows combined aura detection. motw + gotw, all 4 mage int buffs, etc. in one status.

Helps you see the Halion's Corporeality during phase 3

Add in keybindings to place raid marks on mouseover, or the target if there is no unit being moused over

Spy on your guild.

Good old LibTourist-3.0 for WoW Classic Era

Show a bar indicating the attack power gained from Vengeance.

Displays both Kalecgos and Sathrovarr the Corruptor hit points during the encounter.

Gnomish math at its best!

PowerDisplay

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

A Coordinates Data Broker plugin.

Reputation Statistics - Gained, Needed, Rep/Hr, Session Time, etc.

FuBar_WarriorAlertFu

Shows the group leader, raid assistants, and master looter in Grid.

A FPS Data Broker plugin.