I always liked the Borg cubes from Star Trek. I mean, most spaceships have a somewhat aerodynamic shape, probably because that's what we're used to seeing when it comes to crafts from real life (planes, cars, boats...). But in the vacuum of space, air resistance doesn't matter anymore, so you can imagine the collective saying to itself "f*** it, cubes are faster to build and fly just as well!"
I just think the whole ship design reflects the mentality of their creators quite well. Not only does it show a machine-like efficiency and a strictly structured way of thinking, you can also imagine those cubes being easily connectable to form bigger structures (not sure if they ever actually do that in the series though...), reflecting on a bigger scale how the collective, too, is made up of billions of small units. It's just an example of a well-rounded overall design concept is what I'm saying.