BattleMech: Any game using ideas, machines, weapons, or 'mechs similar to the FASA BattleTech series. This includes all 'Mech and "Giant Robot" games, including titles that are not explicitly from the FASA universe (Earthsiege, etc.). Part of the Non-Sports Themes category.
You can browse through games in the MobyGames database that are part of this genre via the game browser.