WowAce

Battleground Timers in a HUD around the Blizzard BG status

FuBar_CRDelayFu

FelwoodFarmer

This will keep track of how much you have paid per item in your inventory. Only one of (Auctionator, Auctioneer, AuctionLite,...

Manages tracking of raid attendance, loot, and more.

Quality of Life Tools for Group questing/leveling

KoS-Management Tool

Resizes some default UI frames (GuildUI, LootFrame, RaidInfo, TradeSkillUI and TrainerUI) to show more lines

GonffBar

Gives detailed descriptions of particular localities, as zones or instances, and provides optional TomTom integration.

Mapster's Minimap brother

Monk Brewmaster/WindWalker Priority and Buff/Debuff Tracking Tool

Adds a couple of graph displays to Skada.

Display an informational fighter jet style HUD while flying or riding

CharScanner scans Basic Character Data, Talent Specifications, Equipment, PvE/PvP Achievements, PvE Boss Kill Statistics and ...

HunterAEP

Transcendence Monitor for Monks

NRT_EPGP

PoisonMenu

JasonQuest