The latest printings of the Castles & Crusades Player's Handbook* and Monsters & Treasure* are now up on DriveThruRPG*. The editing, art and layout has come a long way IMHO since the first printings. I picked up both books in dead tree form at Gen Con this year and I am very pleased with them. You could run a very satisfying campaign with these books and nothing else (although getting the Castle Keeper's Guide eventually sure would be nice!).
I really think C&C has almost the perfect amount of rules detail for me. Not too light and not too heavy. If you are looking for a new-school fantasy RPG with lots of old-school flavor, I can't think of a better choice.
*Full Disclosure: These links include my Affiliate ID. I don't want anyone to think that I am trying to be sneaky!