WowAce

lern2count adds ABinfo castcounts to spell and actions. It has a builtin reagentcount too.

Dims action buttons.

Quality of Life Tools for Group questing/leveling

LilSparky's Workshop mod for Trade Skills

Mutt (Macro Update Target Tool) provides slash-commands that can patch the predefined targets in your macros.

Show all the leyline taps in Suramar

Save and load macros.

Tracks skill and tradeskill costs and progressions, as well as trainer locations.

FuBar_VoiceFu

FuBar_DuraTek

Gathers statistics on certain chance-on-use spells, also known as procs.

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

Adds party/raid role icons in useful places

Stores a browsable database of spells that mobs cast

Cartographer_Trainers

Acolyte2

A tool to appraise, estimate, or judge your equipment against the equipment of others.

Collects, analyzes and presents information about the virtual economy.

Cartographer_nnTrainers

Alternate Rune Display