My personal favorite is Cape of a distant Worlds. It's the 5th most used map, but it is still quiet peaceful. Not many trolls or power players usually go here, which is good. I like the little hills on the sides of the Cape, they're just fun to jump around on if you're bored.
By the way, I don't like Last Cave very much, it's a bit TOO quiet, plus it's where many people go to mate. Plus, it's very plain. Glitches also happens occasionally.