I like the Element 115 ideas. Using an isotope unavailable in our neck of the woods to bend space to your whim. Why burn coal & take centuries to get somewhere when you can just punch in the coordinates, bend the space in between, and step across. Different drives for interstellar and local transport. Sure makes the UFO sightings moving at impossible speeds and changing directions seem more plausible. Why punish yourself with a 25g change of direction, when you just make multiple, rapid, small bends in local space.
Given that Idea, if you had the whole universe as your playground, would you really bother stopping @ a hicksville, hillybilly planet, out in the back 40? One with a bunch of morons running things that can't even tell if they're boys or girls? With nuclear weapons they might cap off @ a moments notice? Things are much more interesting downtown, with binary stars, quasars, gas giants pulling themselves apart, black holes gobbling everything up.