Uhh
Recount, a damage meter
Quest Helper, tells me what to do in quest
deadly boss mods, timers/alerts on boss fights
xperl unit frames, different unit frames than default
afflcited3, arena addon that shows other players cooldowns/abilities
spell alerter by kollectiv, shows icons of spells being cast by mobs/players in your area
dominos action bars, bars to place your skill/macros
atlas loot enhanced, shows the loot which each boss drops
av preform enabler, allows for easy/simultaneous bg queueing
auctionator, allows for storage of auction information/various AH tools
power auras, whenever you gain a proc buff, you have a visual graphic which pops up to let you know
Mik Scrolling Battle Text, combat text thats better than default
gladius, arena unit frames to show the other teams players/hp/other information
Elkanos Buff Bar (EBB), a different solution to default buffs, it shows them in bar form
ClassTimers, provides bars for your various buff/debuff timers
NeedToKnow, similar to class timers
oRA, raid tools that allow everyone to know each other coolsdowns, durabilities, items in your inventory, latency, etc.
Grid, raid frames
Quartz, modulated cast bas, vastly superior to default
Aloft, a nameplate addons. greatly extends the range of name paltes/gives far more options/better visuals, but it is very memory intensive
Cooldown Buttons, an addon that provides icons to track your self cooldowns
Error Monster, blocks errors
Dr Damage, provies information about your abilities. Such as how much harder X ability will hit for if you gain Y stat
Omen, a threat meter to show who has how much threat on a target
Proculus, tracks your item/ability procs
OmniCC, puts a visual number over your tooltips that show its cooldown
outfitter, allows you to easily change what gear-set you are using.
prat, a chat addon. makes your chat windows much more easy to read/more options
tankpoints, a tanking addon. gives statistical inforation regarding how much youll gain from dodge/parry/stam
Rating Buster, compares items/gives breakdowns of stat. for example, an item drops, itll compare what you will gain/lose. it also converts rating into percents
Simple Action Sets, saves your action bar settings, so if you ever respec you can just load your previous action bars
SimpleMiniMap, a minimap addon that adds more options
tiptac, a tooltip addon
totemtimers, a timer for shamans totems
i think thats it