For insane driving madness definitely Death Ralley...love that game! Also Timesplitters, I edit my own map , I make a small room and put 2 of the big ass machine gunner posts side by side then have 2 spawn points for the enemies then start up and lay waste as they attempt to get close to you! MUHAHAHA now thats fun.

Other than that Postal...is the best for all around carnage...where else can you run into town and toss motolov cocktails into the middle of a marching band and watch them explode into blood!!! MUHAHAHA