Flying Saucer: Mostly averted.  While most people do like to build their starships with a certain degree of unnecessary style (and thus, a bit less like an explosion in a girder factory than one might think), the saucer shape is actually not one of the ones that matches up terribly well to convenient arrangements of parts; so there really aren’t all that many saucer-shaped ships around.  When there are, it’s usually because the ship in question has a gravity wheel, which in turn means that the thrust axis is usually parallel to the axis of the saucer, not perpendicular to it, so they don’t move like them, even if they look like them.