Histidine's Must Have list

I love downloading addons of all kinds using the Curse Client, since its so easy to simply pick one up, try it, and remove it if it sucks. The ability to customise Blizzard's at-times clumsy UI is priceless.

Firstly and most obviously, Questhelper. If you don't have this you should. An absolute, unquestionable essential. Where are the mobs for this quest? Who drops the item? Where do I hand it in? How long will this flight path take? QH will tell you.

Secondly, Pitbull. I hate the stupid default party frames with the excessive floral outlines and portraits, so I downloaded Pitbull. The insane range of options and settings and possibilities mean your UI can look exactly however you like. Mine is now simplistic and functional, but you can rearrange it any way you like. Party frames on the bottom left with chat spread across the top; targets on the bottom right with target-of-target above it in a small rectangle; cast bars for them by the side filling up from right to left in green? Slightly mad....but doable. It has rivals: X-Perl and Grid do similar things with X-Perl being easier to use but less customisable and Grid being incredibly (sometimes overly) condensed.

For any healer, Healbot is crucial. It eliminates the time spent selecting players and moving the mouse around the screen by allowing you bind mouse buttons to heals and then simply click on a name. Similarly customisable; mine also informs me when my buff is about to drop off someone, and also when a curse or poison (dispellable with shift-mouse button-4 and button-5 respectively) appears on them. Saves valuable seconds, which any healer knows can make all the difference. I tried using Clique (which allows clickcasting on the default Blizz UI as well as on X-Perl, Pitbull and Grid) but I ended up preferring Healbot.

For anyone who uses different item sets, Wardrobe is sweet. I switch from a tooled-up healing set to my feral tanking gear to a nice purple robe in one click, for wandering around Dalaran in style or changing gear sets. Essentially useless but kinda satisfying.

Deadly Boss Mods. Do you ever go into dungeons? Then get it. Enough said.

Bartender. I currently use the fourth version of this, and it again cuts out the silly gryphons and unnecessary space around your action bars, as well as letting you move them, resize them, recolour them, hide them until moused over, hide them in specific shapeshift forms....etc. Again used to minimalise my interface.

Acheron will tell you what just killed you, so you know in future what to avoid. Or it'll tell you how that nub pugger just died, so you can berate him appropriately.

Baudbag combines the five default bags that you have to click on individually into one big ol' sack. Simple, but god I miss it when it isn't there.

BottleCaps filters all messages that are sent ENTIRELY IN CAPS and presents them to you in lowercase. Sounds good? That's because it is. You'll never see OMG WTF LAG again.

FloTotemBar is a useful shaman addon that condenses all of the (many!) totem options into a small custom interface that you can move around the screen. I use a similar mod (Necrosis) for my warlock, and another one (MageFever) for my mage.

Persistence of Chattiness is a snappily named mod that simply ensures you never type into the wrong channel again. You were talking in Officer chat and suffered from "I forgot to put /o in front of my bitchy message" syndrome? Never again. Also works with /1, /2 and /4 channels.

Quartz is a castbar addon that has so many custom settings it can be quite daunting. Once you master it though, it helps deal with persistently heavy latency by putting a red lag-zone at the end of the cast bar. Since Blizzard receives orders for new casts before the old one is finished, and queues them, you can set up your next cast even if lag is preventing you seeing the effects of the one you're doing. It sounds confusing, it is fantastic.

If you respec regularly and get sick of endlessly clicking away five times to get the points where you already know they should go, grab Talented. Save talent trees beforehand and with one click following a clearout, put all the points instantly where they should go. No more expensive misclicks, or Alt-tabbing out to check that X talent is better than Y talent before putting them in.

RollTracker will automatically open a window whenever someone in your group or raid does a "/roll", and it will track them in order with the highest at the top, highlighting repeat rolls in red (numbering them as well) and also alerting you if someone does a "/roll 99-100". Clearly a raidleading must!

Hope this was useful!

so what part of the game do you actually do? :p

I actually have all of these, on top of that I use a Co-ord program, Baudbag and Quartz.

That is an impressive list...
I use some of them, but others I can't... simple because; 1) My computer can't run it, 2) It isn't entirely necessary for my class or function.
:3 Either way, it's still a very long, impressive and daunting list.
Ah well. I also use some hunter add ons, but that's about it.