WowAce

Hunter 'Misdirection' activity and cooldown monitoring for raids/groups. 'Readiness' aware.

Melee stats Data Broker plugin.

FuBar_KungFu

Adds easier gear switching to FuBar.

Reverse Engineering will drill down and search your tradeskills for their elements

VendorSearch adds search features when buying items from any vendor

Welfare Epics

Adds trinket tags to SUF

Configure which layout or profile to load on entering a zone

TickTo

Tool for easy task assignments in raids.

Allows movement and scaling of class-specific resource displays

Minimalistic LibDataBroker-based guild display

Prints combat duration to chat after each fight

Write event handlers in a simple GUI in-game

ControlFreak

IFrameManager

Synchronise friends among your characters

BetterMagnet

Simple embeddable publish-subscribe implementation.