Pz8 is a series of two-page wargames rules. Among them are is a set of free wargames rules for coastal actions.
Miniatures Rules
Giant Stompy Robots Rules
Meca Tac – The Giant Stompy Robots Edition is a set of free wargames rules for Mecha battles.
King Of War Historical Ancient Battles
The Hour of Wolves and Shattered Shields site has a set of free wargames rules for Ancients Battles based on the free set of fantasy wargames rules called Kings of War.
Dungeon Tiles To Print and Play
Quests of Legend has a nice collection of dungeon tiles for you to print out and use for your role playing or miniatures games (or both!) in a dungeon crawl.