For everyone who hates game XX there is another person out there who raves about game XX. And that's okay. I think that if each group finds a game that fits their game style everyone can be happy!
So, for you folks switching to 4E, what did you enjoy when you first started playing 3.x?
A great question. When 3E first came out I hurried out to buy all of the rulebooks. And played it right away. I won't claim that all of my thoughts below occured on day #1 of playing 3E, but these are a blend of reflections after a decade of 3E being out there.
While I didn't like the details (feats, skills, etcetera) from a GM's perspective, I loved those same elements as a player. I think it's cool that fighters get things to do like Cleave foes. I think it's neat that magic-users can tweak spell duration or spell damage or other factors to make them do what the player wants. As a player I like the fact that there are more options than many of the older editions.
From the onset I'm glad that 3E came with a free character generator program to handle those details. And that I could take my character and print it as a PDF and save it for later. Those are nice "modern" details that made 3E play more fun than it might have been otherwise, because character generation can be tricky if you're only partly familar with the rules. (This was another 4E perk at first, but I think they took down the free chargen program for 4E. Also, it only worked for levels 1-3, which was very limiting and partly led to my lack of enthusiasm for the game once we'd played 4E for a while.)
Mechanically, I think that 3E does some great things. I like the fact that pretty much every action is done in the same way with d20 die rolls. I like the unified XP charts so characters can all advance at the same time. I like the fact that AC gets bigger as the armor gets better. I like the fact that the attributes are more open-ended and can continue go as high as we like. I like 0th level spells, and the notion that low-level magic-users can cast more spells faster (e.g. the Sorcerer class). I think that it's great that 3E reorganized the rules in a logical sense.
I like the fact that 3E was relesed under an OGL so that others could create rules sets based on those rules. Without the OGL I'm not so sure that C&C, Labyrinth Lord, DCC RPG, and others would be possible. At least, they wouldn't be able to have the same style and general rules patterns that they have at present.
So overall I'm a fan of 3E and what it represents. I wish some of the older editions were still supported, but other games are clearly filling that niche at present.