Jetpacks always, I will use lifts if I'm carrying or need to move something big or heavy or it's a lot of floors but I generally prefer the stairs as I've always had a fear of getting stuck in one. I kind of don't know how I never got stuck in one of the lifts at the place I used to work at as they were pretty run down and always breaking down, the fact that they'd lost the key that let you go to the basement floor and you were required to take a spoon to turn the lock instead never filled me with confidence.