Acies is a very nice looking two player card game designed to simulate conflict between ancient armies. it looks like it would be a fun thing to play on off-nights when your regular miniatures games end early. All the parts you need are there to download and print out.
Brickquest is a set of free miniature wargames rules for dungeon adventures along the lines of Heroquest or DungeonQuest. The catch here is that it uses Lego guys.
Combat Action is a very complete universal wargames system by Fabio Fontana. He writes:
Combat Action is a strategy game of small scale conflicts. It can be used to represent skirmishes with a dozen models per side up to larger conflicts with multiple squads, vehicles and support weapons. The system presented within this book comprises two levels of detail, a simple system for small scale games where each model on the battlefield is a separate unit, and a more complex layer which adds optional rules to govern targeting, simulate chain of command and allow larger engagement of forces.
The point system will allow you to design any creature, vehicle or model you like, and field any model you create on the battlefield.
The site also has playscreens, scenarios and a complete world background.
John Cooper has sets of downloadable hexes for making your own wargames maps.
You can never have enough dice. And no matter how many you have, I'll bet you don't have any that look like this: