Wargames Rules 1685-1845 is a set of classic WRG rules from 1977. I own a copy, but you can get your own in pdf form at the link.
Miniatures Rules
City Grounds Fantasy Skirmish
City Grounds is a fantasy skirmish game in the vein of Mordheim, but with different mechanics.
Starship Marines Boarding Actions Miniatures Rules
Starship Marines is a set of free wargames rules for Starship boarding actions. This is quite a detailed set, and is continued in Starship Soldier.
Stingray, Stingray, Undersea Rules
Stingray, Stingray is a set of free wargames rules simulating the 1960s television series Stingray.
Fire At Will
Fire At Will is a set of free wargames rules for 6mm fantasy battles.