Action Bar Saver2http://www.wowinterface.com/downloads/info8075-ActionBarSaver2.html
A great addon to save positions of abilities and macros, and load them on demand after spec change or talent resets.
A simplistic minimap. Square style.
An addon no druid can live without. Highly configurable, contains many modules, easy to setup. It simply has it all.
A cache using Inspect addon, with additional gear and stat numbers.
An outdated, informative and addon handling panel addon. Check out Bazooka, it is similar but more modern.
Another outdated, trinketmenu addon. I am using it for many years now, it makes itemswaps so much more easier. It also can queue up swaps, finish it when you leave combat. Also handles gearsets.
A pretty new addon, which shows the duration of configurable cc's on you. Easier to spot, follow.
Miks Scrolling Battle Texthttp://www.wowinterface.com/downloads/info5153-MikScrollingBattleText.html
A controversial addon. Some hate it, some love it. I am in the last branch. My favorite function in it, are the custom created triggers which give you a lot of freedom in announcements and alerts. That's how my Skull Bash trigger was born: )
Cooldown tracker. Also shows remaining cc durations on enemy profile pictures.
Bag addon. Bigger, more managable.
Recoloring out of range abilities, macros.
A beautiful, informative nameplate addon.
A castbar addon, which I use mostly for its focus bar. Highly configurable.