Mass fabrication. With mass fabrication,I have a supply of mass limited only to how much space is available to me. Since mass fabricators take an incredible amount of power to run,I'll also be getting reactors to keep them online. This,in turn,allows me to create an insane army,comprised entirely of Soul Rippers,Fatboys,or CZARs and Galactic Collosii in safety behind my stone wall defenses,upon a carpet of SMD coverage.
That,or get like,three Mavors or ten SML's. Whichever tickles my fancy.
But that's for Supreme Commander. It varries from game to game.