WowAce

Allows communication to be shared across realm through Battle.net.

Shows you which bosses you've killed next to the raid finder frame.

Steroids

Adds unreal tournament style sounds to PvP encounters.

aX_RaidStatusConfig

Adds aggro coloring to oUF.

Opacity effect on action buttons in cooldown.

A customizable buff/debuff display replacement for the default Blizzard frames (with right click cancelaura support).

Remaining and rested XP Data Broker plugin.

Relog

Adds notes to item tooltips

Add-on that shows which battle pets can be farmed this week

Manage Raid Queues

Shows who controls Wintergrasp and the time until the next battle.

GratuityLib

SVG Render-bender

Allows you to loot BoP items without prompting when not in a group or raid

Displays how much total honor you have from all sources.

Reputation tweaking module for TweakHub with auto watched faction selection and detailed rep info updates.

Converts commonly used acronyms into hyperlinks.