The only one I can think of is the landscape generator, there's too many options and it's too specific for my liking. I would prefer something like minecraft where you can just walk around, or enter a seed. Then you could have an option for certain dimensions.
Edit: I was actually thinking about doing a contest where the winner who made the most popular one would get a steam game of their choice. under maybe $50 IDK
Edit2: I'm stuped, I didn't look at addons...
