As title says, personally I'm an AD&D 2'nd Edition guy.  I hate 3 and 3.5.

My reasons:

1- I like complicated rules.  Complexity is fun, when youstreamline things too much, games get boring.

2- AD&D was more about Roleplaying a character, if you had a char with 3 as an ability score, you were forced to role play it.  The new editions are too power gammer focused.

3- I spent a hell of a lot of money on books.

4- I spent a hell of alot of money on Magic cards and the basterds then tell me, "Hey, you can't use them in a tournament!"  Go to hell kiss my power-9 Byaitch!  Timewalk FTW!  BLACK LOTUS!

I just bought the 3.5 manuals to gain a better understanding of the D&D online game as well as curiosity, and the PHB is as weighty as the DMG, now how complicated has it got?

I play the 1st ed AD&D with a number of omissions, and some local modifications that have been tweaked over 25 years.

I reckon version 3+ were written so it could be translated to computer easier. Also as a marketing strategy by WotC, and to ensure the brand continues to make money. I remember when White Dwarf was a real magazine, not a Warhammer catalogue, and theres the role model. Another company that change rules regularly in order to maintain profit.

Call me old school, but I have always prefered the 1st edition of AD&D.  I just liked the feel of it and the way it played better.  I also noticed that in general I always enjoyed the modules done by Gary Gygax himself the most.  I think that the man is absolutely brilliant. .  2nd edition was pretty good too, although I did not like some of the changes, but at least it still felt like D&D to me.  I am not a big fan of 3rd edition.  They changed too much in my opinion. 

I also absolutely HATED the artwork in the 3 rulebooks with a few exceptions.  I thought that the characters looked too punkish.  I wish that they would have went with beautiful high fantasy works of art like they had in previous editions.  On a side note I do like how Wizards of the Coast has been tapping into some older source material lately for some of there newest supplements.  And I will always be grateful that they continue to support D&D's growth so strongly.

Lately I have been play the Castle and Crusades rpg which is a nice bridge between old school AD&D and  3rd edition.  For any that might be interested in it here are a couple links -

www.trolllord.com/newsite/cnc/index.html 

www.trolllord.com/newsite/cnc/why_play_cnc.html

I started playing with 2nd Edition using Skills and Powers.  I kind of miss the customization it offered like taking allergies or phobias.  (Nothing like seeing a mage running off screaming when undead rise up because he has an extreme fear of the dead).   But I don't miss the complicated percentile dice rolls. 

I like 3.0 and the changes made for 3.5 were needed so I'm happy with them.   Frankly I just miss playing, having moved away to far away from where my group lives.