Pacific War Naval Chess Game is a hex-and-counter, print-and-play game of World War II.
Battleforce Quick Start Battletech Rules
Battleforce is a set of free wargames rules for getting a quick start in Battletech.
Strongbow Feudal Warfare Rules
Strongbow is the Perfect Captain’s set of free wargames rules for feudal warfare from 1050-1300AD
Expanding Memoir ’44
Here’s an interesting bit on one gamers’ expansion of the Memoir ’44 system to a variety of conflicts.
Juggernauts: Panzerkeil vs. ArtKor, Kursk 1943
Juggernauts: Panzerkeil vs. ArtKor, Kursk 1943 is a print-and-play, hex-and-counter wargame