It has to be a Mac: People can accept giant alien spaceships coming down from the skies and killing everyone, 400 crack Stormtroopers missing everyone who is focal to the plot, and Rambo killing every communist in the world with a toothpick. Unfortunately people will NEVER be able to suspend disbelief enough to accept that a PC running Windows will not crash at the most crucial point in the film, right when the heroes need it to transmit the destruct codes or run the programme that saves the world.