Hussar
Legend
Not sure what else needs to be said really. So, what the heck, I'll just repeat stuff anyway. 
B/E (1980 Moldvay) - What I started with. Looks like a lot of the boxed set games that came back then - Star Fronties, Villains and Vigillantes, etc. You got a whole game in a box (or two). But, you had to do most of the work yourself. They'd get you started, but, beyond some very, very basics, you were on your own.
AD&D 1e - Like has been said, organization was err, lacking? Stream of conciousness makes for interesting reading, but terrible rule books.
AD&D 2e - Power creep from Hell. Books that were just all over the place. 2e seriously lacked cohesion in its design. Compare the Complete Priest with Faiths and Avatars, or, heck, even Legends and Lore and you'll see a huge spread. Some very serious balance issues as well - 2 weapon fighting was just head and shoulders better than any other option.
AD&D 3e - TOO DAMN LONG. It should never, ever take that long to do a single round of a fight. High level D&D can be painful to run if everyone isn't on the ball. Plus, my biggest beef is a number of times that classes get "time outs" because of some sort of bizarre sense of balance where two points of imbalance makes it even. A rogue should not be screwed over going tomb raiding.
I'm not going to comment on any other edition since I haven't played them.

B/E (1980 Moldvay) - What I started with. Looks like a lot of the boxed set games that came back then - Star Fronties, Villains and Vigillantes, etc. You got a whole game in a box (or two). But, you had to do most of the work yourself. They'd get you started, but, beyond some very, very basics, you were on your own.
AD&D 1e - Like has been said, organization was err, lacking? Stream of conciousness makes for interesting reading, but terrible rule books.
AD&D 2e - Power creep from Hell. Books that were just all over the place. 2e seriously lacked cohesion in its design. Compare the Complete Priest with Faiths and Avatars, or, heck, even Legends and Lore and you'll see a huge spread. Some very serious balance issues as well - 2 weapon fighting was just head and shoulders better than any other option.
AD&D 3e - TOO DAMN LONG. It should never, ever take that long to do a single round of a fight. High level D&D can be painful to run if everyone isn't on the ball. Plus, my biggest beef is a number of times that classes get "time outs" because of some sort of bizarre sense of balance where two points of imbalance makes it even. A rogue should not be screwed over going tomb raiding.
I'm not going to comment on any other edition since I haven't played them.