In The Nether - As the name states it has something to do with the nether, the nether in this seed has a quite big open area and has some caves

Jurassic Pork - This world has a large desert area with a few lakes and ponds , it also has a few mountains and caves, one of them lead to redstone

666 - This world has groups of mountains throughout the land with a lot of overhangs and caves, there is also a large desert too

Sosaria - In this seed you will find a lot of mountains with caves at the base of them, even found a cave that led straight to diamonds

lucie - Another seed with mainly water, it has a few small islands and pretty much no trees, but there are a few mushroom bi-omes

Maxwell - This world has mostly water with a few islands, on the islands you will find mushrooms bi omes and even a mooshroom!

notrees - This seed has to vast plains, one being a grassy plain with no trees and the other a sand plain. On the other side of the map you will find a snowy forest area