The final post on the top ten troll questions.
(10). Which is the best edition; ODD, Holmes, Moldvay, Mentzer, Rules Cyclopedia, 1E ADD, 2E ADD, 3E ADD, 4E ADD, Next ?
The original rules, of course. Not because I prefer it, although I do. It's the best because it's the core of what you need to know to play D&D. Everything else is basically just house rules and variants. A lot of it is unnecessary, although it's certainly useful for some people.
I suppose the best written would be Holmes, the most entertaining to read would be AD&D 1e, the most complete would be Rules Cyclopedia (from what I hear, since I have yet to actually look at it, myself. 3e and 4e are the best for their very specific audiences. Next isn't even finished yet, so no need to even consider it.