I actually like both of those machines. For a bar location Starship Troopers might do better because of theme. It has the novelty of the 3rd flipper and the brain bug which might grab people's attention.
That being said I really enjoy Space Station every time I play it. Might be less maintenance intensive than Starship Troopers.
Demo Man might be good, novelty with the gun handles. Something from Data East might also fit the bill as well (LW3 or LAH).