When it absolutely, positively, has to be destroyed on time, nothing beats your own remote-controlled, satellite-mounted laser cannon. A variation of the "Wave Motion Gun", Kill Sats have the added advantage that you don't need to be anywhere near either the weapon or the target. Instead, you can fire it from the safety of your headquarters: your satellite will move into position and unleash a shiny descending Pillar of Light on your unsuspecting target. Power/accuracy on Kill Sats vary, ranging from "lone vehicle" to "entire building" to (rarely) "town or small city." Planet busters are another category entirely, as firing them remotely from anywhere on the surface is inadvisable.