how about a generator that forms like a volcano mountain range with diamonds and such only appearing around the lava and if you dig far enough you will fall into a sea of lava instead of the void and there will be a rare occasional dormant volcano that will be lined with obsidian and have a lake of water in it
what about like a giant rainforest type thing, with big trees and a canopy with lakes inside of the canopy?
Seconded, and could you make an archipelago generator? Essentially medium sized islands (from the center, if your high enough you can see the shore) With medium to large bits of ocean in between, they could feature central mountains, rivers, rainforests, etc.
I just had a fantastico idea! combine a bunch of generators into 1 program with a bunch of options and stuff. So I'll try to gather all your ideas and make it into 1 program that will be released eventually.