I'm interested in seeing what addons other players use. I'm not asking for a full list, I just want to know if there are any "diamonds in the rough" so-to-speak. Addons that are lesser known, but still have a very useful, unique or rare purpose. Or maybe an addon that excels at doing its job, but not many people know about it.
There are only a few that I can think of right now, so here they are:
!sh - blocks "addon loaded" messages in chat pane on startup
BadPet - notifies player/group when a hunter pet uses a taunt
bobFastLoot - bypasses loot window, useful for those that auto-loot all
ExtraQuestButton - makes it easy to use quest items
Shaman Mount - makes it easy for Shaman to mount/Ghost Wolf
XToLevel - older, shows mobs/quests/dungeons/etc needed til you level up