As we view a large scale model of the universe, what would be more prevalent - galaxies or open/empty space?
The empty spaces between "small" clusters of galaxies is much greater than the space occupied by the matter itself.
I once read the following claim, which I believe puts it into perspective:
If two galaxies were to collide and space through one another, the probability that any two massive objects would strike each other would be similar to releasing two flies to fly through the Grand Canyon and expecting them to collide with each other.
This speaks more to the distance between stars than the galaxies themselves. It is estimated that the distance between adjacent galaxies is on the order of roughly 30 to 50 times the size of the galaxies themselves. This is a very approximate figure though, as galaxies tend to exist in clusters, with vast spaces between clusters.