My hands-down favorite source for user-friendly addons that are must-haves is Gazmik Fizzwidget's Superior Gadget and Doodad Emporium. Allow me to introduce you to some of his wares!
Meet FactionFriend. Imagine that you are grinding reputation with a faction because they won't give you something you want until you do (this is difficult, but I believe in you personally). You click into your character window, click onto the reputation tab, scroll down to find the faction, and click to have it show above your experience bar. Great! You're in business.
Now suppose that you want to know how much reputation gain the 283 clumps of dirt you're carrying in your pack might get you, without having to trudge into town, or whip out your calculator. Maybe a guildie pipes up and asks what your rep with another faction is. Also, I submit that the above method involves work.
Enter this discreet little addon. The regular faction reputation bar that you place will not change into scary monsters with swirling numbers that might bite you. It will look as unassuming as ever. But when you glance at it, you'll be able to see a shadow of how much reputation you would gain if you handed in the items you possess, either in the bank, the mail, or on your person. It works just like looking at your experience bar when you are rested.
Another handy feature is that when you move into an area that pertains to gathering rep for a faction, such as a particular dungeon, an evil grabby teddy bear-mole hybrid encampment, or even a battleground, your reputation bar will automatically switch over. In addition, mousing over and clicking on the bar will open a drop-menu with all of the factions, and your rep, listed. No more jumping through hoops, and no scary changes in your user interface.
For the gear-conscious, or drooly, among us, behold the Linkerator. You've heard about, say, Kang the Decapitator. You are, perhaps, in the market to purchase one. You cannot link to it in trade channel because, due to your unfortunate situation, you don't have one. Never fear! Just type [Kang the Decapitator] fakin' it stylez and voila! It will show up, you can marvel at it, ask for it, and everyone wins. You can also easily check to see how your [Ugly Hat of the Monkey] might benefit from an animal-change. Again, might I point out; you can keep the same old user interface that you're antsy about changing.
Fizzwidget also brings us Trackmenu, which we have featured previously on WoW Insider, although it is so discreet, so helpful, and so necessary, that it will actually become irrelevant. In patch 2.3, Blizzard will actually be installing this functionality into the default user interface. Yes, I do indeed believe that Fizzy predicted the future.
Hunters would also benefit from the Feed-o-matic, which helps you stay on top of keeping your pet fed and loyal. In order to avoid spoiling all of this site's surprises, I recommend you head over and check out his helpers for levelling, disenchanting, and other basic, though sometimes tedious, operations.
Now for an addon that let's you be creative! I often find myself gazing at the landscapes in-game, and noticing potential screenshots that would make a charming additions to Around Azeroth. I'm also often frustrated by how limited I find the default camera to be when I'm attempting to snap such a shot. If this sounds familiar, head on over and check out Improved Screenshot. Although you can edit the way your camera behaves by physically going in and changing game files, this is a much simpler solution.
This next addon will actually modify your UI. A teensy bit. Can you handle it? It let's you change your fonts and their colors to make them easier to read! When I discovered ClearFont2, my eyes just lit up. That's right; it gives you a +2 to your tired gamer eyes resistance.
For actual, full-blown alterations of the default UI, I must confess that I am the product of a gnomish poultryizer. While I fully realize that if I logged in and my hair turned white from shock, I could always hit "disable" and grab a box of $8 hair dye, I still can't bring myself to try it. In fact, even purely cosmetic changes like making all of your buttons round and pretty lead me to think, "but what if I can't recognize a button I need in time?" Although, if you read that and thought, "round buttons you say?" and you don't cry when I say "pink" then say hello to a funky custom UI.
Although I've not been too adventurous yet, I can definitely brag that my l33t UI looks "perfectly similar" to the default. In fact, if I captured screenshots of enabled/disabled, we could all play a lovely game of "spot the differences", as long as I disabled my threat and damage meters.
Do you know a simple, can't-live-without-able addon? Are you itching to push me into trying a custom UI you like? Did you come from a background of reluctance before being ushered into the addon world full force? Let us know!