Labyrinth Lord is the new favorite in the Lair (at least amongst the minions). I can really get behind it as it's all about Basic D&D cleaned up and totally free. I bought the Minions copies of the basic D&D books of my youth which I found on EBay. I then sat back in shock as they proceeded to trash them in the same way 10 year olds all over the world trash their books. No disrespect intended on their part.
Hell, they love playing D&D, but they are just hard on books. This is where Labyrinth Lords comes in- everything you love about Basic D&D but free and downloadable-over and over. Labyrinth Lords is available at Goblinoid Games. They also have a lively forum. Give it a look.