I'm not too creative, I usually just make things with redstone (mob traps, automated farming, elevators, etc...). And I prefer survival, so I never really build too much eye candy in the fears that a creeper will just eventually blow it up. My Mom and Sis however are much more creative than I am so I set them up a peaceful server to play on.
My sis built this on my server recently (she is now making the hot air balloons):
And the night shot:
I'm zoomed out pretty far, but on the inside it's pretty big, she spent a whole week on these.
My Mom also built this off of a model for a mall she found online:
day:
night:
And to give you an idea of how large the map has gotten, here is our peaceful map zoomed all of the way out (the areas from the images above are circled). I have to keep expanding border guard because they keep hitting the limit and they want to spread out: