I love spiral galaxies... Not that I hate elliptical ones, by the way. I mean that I just, well... you know.
Spiral galaxies ought to be impossible. They can only exist due to dark matter, which is a totally mysterious substance, is inexplicable (the Standard Model cannot explain it), and seems to be just there.
I think God created DM just for the aesthetics to make the all those galaxies look cool and interesting with all those elegant spiral whorls. Otherwise every galaxy would be the same, a featureless fuzzball, and they would all look really dull and boring. With DM every galaxy is unique, like snowflakes.
Post-it galaxies are my personal favorites.