Dungeoneering dot Net has a nice selection of printable terrain tiles ostensibly for use with the Dungeons and Dragons miniatures game, but which would also work with any number of dungeon crawl games — of which there are many free ones available on this site.
Print-and-Play
Rusty Industry Print and Play Game
Rusty Industry is a free print-and-play card game about building and trading
Rusty Industry Rules
Rusty Industry Cards
Renfield Card Game
Cheapass Games offers Renfield, a card game about parts, tools, gravestones and “yummy delicious bugs.”
Unbound: Endless War
Unbound: Endless War is a free print and play game for two p layers in which you build a map and attempt to take over a players’ bases. It’s a pay-what-you-like game.
Glider Pit Gladiators Board Game
In the world of Glider Pit Gladiators,
Two to six players control primitive gliders descending into a deep, sheer-walled pit. Within this natural arena the glider pilots engage in ritualistic, nonlethal gladiatorial combat. A combination of martial and flying skills is required for success in the glider-pit. Every decision a player makes, from the selection of weapons to the anticipation of fickle air currents, can be the first step down a road to glory… or disaster.
I think that this would make a really good and visually striking miniatures game.