What is your favorite story setting?

I want readers and writers here to understand what is popular, what isn't, and why they are that way. I also want people to get a feel for what is being done right about some types of stories and also knowing why some stories just seem to go bad all the time with certain settings. So, without further ado, I propose these questions.

Question #1: Which is your favorite and why?

Question #2: Which is your least favorite and why?

Question #3: Choose any category: What are common mistakes people make that writers should avoid?

Note: Poll is multiple choice. Only choose more than one if you CAN'T DECIDE between them.