I like 4, 12, and 16 the most. I believe 4 is simple but effective while 12 and 16 remind me of luxury and honestly just my favorite. There's also lots of variations using the same base idea for those 3.
This is my candy castle. I got the idea while messing around with the materials and seeing how shiny and bright you can make the colors. It wasn't my initial idea but I'm happy with how it came out. One thing I struggled with was adding windows and doors using boolean difference. (Did figure out boolean but decided to keep it simple)