D&D B/X Basic Rules

I am not sure what edition of the original Dungeons & Dragons game brought more players into the "fold" as it were. I suspect it was the BECMI version of the game but I think a strong argument could be made for the B/X edition. I never want to slight the little brown books but I don't know that they can be considered the same as the more polished retail offerings. The Holmes blue book was great but I think this was the first retail version that opened the game up to the general publis and caught their attention. I still have very fond memories of  these even though I was entrenched in AD&D long before these were released. These can still be picked up cheap on eBay or you can go the new OSR versions if you prefer but either way I suggest checking out how Mr. Moldvay put a spin on the genre we all love.

From the back of the book:

DUNGEONS & DRAGONS fantasy game is a step out of the ordinary. Each adventure is like writing a novel. Players assume the roles of elves, dwarves, halflings or humans and travel through a fantastic world filled with danger and excitement. Adventurers will wander through frightening dungeons conquering evil foes and meeting terrible dragons.

DUNGEONS & DRAGONS fantasy game is the original "role playing" and this booklet makes it easier than ever to play. This rulebook contains all the rules needed to begin playing and running DUNGEONS& DRAGONS adventures. The rules have been reedited and organized so that people who have never played the game before will be able to begin playing with a minimum amount of preparation. DUNGEONS & DRAGONS fantasy game can be played by anyone. The entire family will enjoy a DUNGEONS & DRAGONS adventure. And with more than 100 monsters included in this booklet no two adventures will ever be alike.