chemical-weaponry, nanite-nomnomnom-swarms, Von Neuman berserker drones, infection of bio-sphere with non native bacterias and viruses and my favorite: small projectile given a near-luminal (or at least very high) speed (railgun?) and colission course. "Vanilia" Nukes are too streamline. Back on topic I believe houses are capable of easy production of anti-matter but they can't get any significant ammounts of it.