Gee Theillik! What a great idea! Why didn't I think of asking everyone what their preference was on this topic? You're a smart guy
Personally, I like 2nd edition.
My reason? Hmm...I think that kits and such provide a much broader range for rp. 2nd edition is more geared towards rp, than towards fighting, like 3rd edition. 3rd edition is more like..a video game. 2nd ed has basic classes (Warrior, Wizard, Rogue, and Priest), and from there you can branch your characters out in any direction you wish to go. 3rd ed only has a few classes, and that's it. You cannot go anywhere else from that, except to prestige classes, which takes a long time to attain.
I find that spells and proficiencies are not rigid. There may be few of them, but they are broad enough that you can use your imagination (heaven forbid) to expand on them. Leaving what happens in the game to the player's choice. Spells in 2nd ed allow for reversable spells and more manipulation of arcane power, while 3rd ed you have to have the specific spell or you're screwed.
Personally, I find the 3rd ed and 3.5 ed books far more complicated than the 2nd ed books. 2nd ed books, for the most part, are clear and precise. 3rd ed takes forever to get to the point.
As DM, 3rd ed is very rigid. If you follow one rule, you have to follow them all (i.e. attack of opportunity for charging - feat: improved bull rush). It is sooo time consuming for a DM to search through the 3rd ed books for anything. I find 2nd ed to be more flexible. Yes, there can be rigid rules, but they are more guidelines/optional rules for the DM. The DM can take the game where he deems necessary. Can this be unfair to the players as they don't necessarily know how things will turn out? Yes, but it's not about fair; it's about roleplay.
A lot of people hate the AC vs Thac0 deal in 2nd ed. I can understand this. It is difficult sometimes to calculate Thac0 and AC, etc. The d20 system is definitely far more simple. Although, I find myself wishing that I was using more of my dice, than just..a d20 and a d8 or a d20 and a d6.
Building characters in 2nd ed is far faster than 3rd ed. Why? Because 2nd ed is designed to create basic PCs (with kits they can be more specific). From the basic PCs you, using that imagination again, build your character.
Monsters in the 3rd ed MMs are designed for combat, as opposed to rp. Not saying that rp is totally wiped, but they are definitely designed for combat. Have you ever played a completely combat-oriented game? It can grow extremely tedious, nod nod.
What I like about 3rd ed: I love the sorceror class. In fact, I have adapted the 2nd ed Wizard classes to be sorceror's instead. I can appreciate the simplicity of the d20 system, but it's not necessary. And I think they have a lot of new ideas which are really interesting, and some of the pictures are cool. Although, the picture of the Invisible Stalker in the 2nd ed MM is the best picture EVER!
But I also think that it depends on who you play with. The true gamer seeks roleplay
My final conclusion, after all those scattered thoughts, I'm going back to 2nd ed. 3rd ed is too much like a hack-n-slash computer game.