I do love me some Pathfinder though. More importantly, my group loves it too.
Pathfinder sits at second place for my favorite "D&D" edition, mostly just because familiarity breeds comfort. I am comfortable with its rules, can run it almost from memory (seriously, I've accidentally memorized more monster stat blocks and level progression charts than I care to mention), and do love what Paizo has accomplished with the D20 system and the Open Gaming License. However, it is not an easy system, and Dungeons and Dragons 3.0 and 3.5 are arguable less easy (and have a much larger glut of books to wade through). In the D20 vein, I've played Castles & Crusades quite a bit and own and have read and run a session with Lamentations of the Flame Princess, and, while I love the simplicity of the rules in both games, C&C has too much nostalgia for the sake of nostalgia (and the wonky SIEGE Engine mechanics for stats), and LotFP has some really gross art*, the classes have too little crunch, and I hate races as classes.
However, the Grindhouse edition of LotFP is awesome. I also need to pick up Vornheim.
I ordered Basic Fantasy RPG, and do like the look of it, but haven't gotten my hands on it yet to make a decision. I've also been DIY hacking together my own D20 retroclone-ish pile, and the test session this past Sunday went really well. Still, I have a lot of work to do with it. I've never played OD&D or any of the weird sub-editions or box sets, so that obviously can't be my favorite. That leaves AD&D 2nd Edition. I've barely played AD&D past a few sessions in my high school years, meaning that it really has no right being my favorite. Honestly, all sword and sorcery systems blur together for me, so my "favorite" is a nebulous concept, meaning AD&D 2E might not actually be my favorite. THAC0 is kinda dumb, I hate that there are no Half-Orcs, I hate stat restrictions on classes, and I hate rolling 3D6 straight down for stats. However, once all that is stripped away and house ruled (which is fine, because I strip down and house rule all Sword & Sorcery games), it has a beautiful, simple core rules set, is written well, and it has all the whimsy and sense of adventure and exploration I want in my D&D.
Plus the PHB is freaking awesome looking!
Of course, the fact that most of the books are dirt freaking cheap helps. I got the Player's Handbook years ago for $5 at a garage sale, got my battered Dungeon Master's Guide from the clearance used book shelf at a local comic shop for another $5, then paid $11 (including shipping) for the Monstrous Manual off of Amazon. Twenty-one bucks for a full on roleplaying set is pretty amazing. It is on my shortlist of games I want to play in the very near future, and my fantasy world that I (like every nerd ever) am working on works very well with the whole AD&D feel.
The Dungeon Master's Guide also looks sweet. This is my favorite RPG book cover ever.
One of the biggest draws of AD&D for me is the artwork. I draw, took art classes my entire life, my parents took me to art exhibits and museums and instilled a love of art in me, and I spent half a year in college thinking I would be a fine arts major. I am an artwork snob. While I love the Dungeon Punk style of Pathfinder and D&D 3.X, I adore the high fantasy artwork in AD&D. Sure, a lot of it is crappy, but you get that in all RPGs. The awesome stuff and even some of the mediocre stuff is rich in non-setting-specific atmosphere and practically begs to be set loose in a campaign.
Look at all the Beholders! Look at them!
So, AD&D 2nd Edition is my favorite, at least for now. Hopefully, I can play it soon and really make sure it stands up to my expectations like I think it will. Worst case scenario, I will idea-mine it for all it's worth like I do everything else.
*While I love LotFP's art, it's a giant turn off for most of the people I play with, meaning that I count it as a detriment. Anything that causes me to possibly lose a player or a game is to be avoided.