I remember a nifty little mutator for Unreal Tournament where ammo boxex would explode when shot. There were also some cool ones, such as trails of blood being left while you were wounded. OH! There was a a great one that I absolutely loved, where upon death, your corpse would rise as a zombie while you respawned normally. So, after playing for several minutes with a few people, there are hordes of sporking zombies roaming around