Best to worst for me is Plains, Mountains, Meadows, Mistlands and Black forest. I think everyone can agree mistlands just isnt fun, the fog made it very ugly and the terrain is what really makes it a bad experience, when coupled with the games poor hitbox problem (for the player, obviously this doesn't apply to seekers with their generous attack hitboxes). I really do feel like Mistlands is a sore spot and hopefully not going to be repeated again with the next two biomes.

Black forest is a biome that is in severe need of an overhaul, it's boring, and there's little reason to come back later once you're done with it unless you need core wood. Copper mining is also awful and a very bad first impression of the game, taking significantly longer to get the amount you need compared to all biome metals after it, just so you can make the worst metal equipment in the game. Also terrible for sailing since there's always rediculous amounts of rocks on the shores.