Command and Conquer Renegade
Thanks to Dante for the Heightfield tutorial, the PillBox model,and the Bridge model from said tutorial. unzip file to westwood/renegade/data directory can be played via MPLAN or MP PRACTICE, for MP Practice mode modify the svrcfg_skirmish.ini
A very huge and beatiful map with automatic and player controlled gun emplacements. There are many bots in the base, so they can easily blow up your rushing vehicle.