DungeonMaester said:So..I will try to do justice to all the information every one was gracious to provide for me.
while there is only one oD&D, there are alot of editions that came out after it, each with some of there own rule sets expanded on..In a way it is like 3.0 to 3.5. (IN A WAY) So, because oD&D used their own rules in each game anyway, I cant really go wrong with any of the rulebooks. (Except RC, which multiple reports say its horrible written and/or Edited)
I'm not entirely clear on what you are looking for from OD&D - any of the editions mentioned in this thread (white/brown box, Holmes, Moldvay/Cook, Mentzer) will give you a game that is mechanically lighter than D&D 3E and requires more GM adjudication/judgement.
In terms of ease of play, though, I wouldn't recommend white/brown box. Those rules are horrible to read. Moldvay/Cook is a pleasure to read, and tends to produce a somewhat light-hearted relaxed game (that is not to say it couldn't be used for a more serious game).
I don't know the Mentzer rules outside the context of the RC. I gather its Basic rules are, in content, very similar to Moldvay. A good review of them on RPGnet is here.
By the way, I don't see the RC as horribly written or edited. It is a pretty good book, and I think provides a pretty playable game, although mechanically more complex than Moldvay/Cook. (But less than 3E D&D - I'd say about the same as AD&D 1E, but with much more clearly written mechanics.)
DungeonMaester said:My next question is about Classes.
Do RC, D/X. Or CD&D cover more then the three classes? If not, is there a 'magic bullet' Class Cyclopedia? Or do I have to buy up other Supplements?
I think you are looking for a degree of definitiveness that OD&D and its descendants do not provide. For an interesting discussion of the history and flavour of early D&D gameplay, see here.