My go to 1 shot for OSR adventures. I print out a bunch of generated characters from http://character.totalpartykill.ca/mazerats/ and have all we need for a fun night.
-The spell system engages the players and GM to make a cool story based on the word pairings
-The tools table puts a focus on solving things through being clever over brute force
-So easy and quick to get going, yet gives you all you need for a night of dungeon delving.
[5 of 5 Stars!]