I like the OSRIC rules - previously mentioned in this thread.
I bought this AD&D (1st ed) clone from Lulu in one lovely handy volume - precisely because it was one handy volume.
OSRIC 2.2 rules on Lulu
I think Brave Halfling Publishing have also released they're own edition (must double-check I have the right publisher here)
One of the advantages of the Old School Reference Index System is that it allows publishers and writers to publish new modules for the old rules whilst still remaining within the Wizards of the Coast Open License Agreement.
However, be warned, there are a few very minor differences, for practical and perhaps legal reasons, between AD&D and OSRIC which mean that the different rulesets can conflict when used together. (If I find the right link, I'll post it here.)
However, perhaps you now have a copy of OSRIC in PDF or hard copy, but you don't want your players to have full access to the monster stats at the gaming table. Rather than a large compendium, what is required is a Player-Character's rulebook, or "handbook", nay a "Player's Guide"