I keep finding myself going back to Moonlight Falls, even if I have started playing the family in another city. I just really love the Victorian look that it has and the arboretum is one of my favourite places, I often send my sims on dates there, they just enjoy the garden, watch the stars and look for fairies all the time ;) I often play families where at least one of the Sims is a supernatural(in my current family all of them are actually) and I think they fit more naturally in Moonlight Falls. My current family started off in Twinbrook which I actually enjoyed quite a lot, but my female sim got an unexpected inheritance in form of a huge abandoned Victorian mansion(still WIP) in Moonlight Falls, just in time for the arrival of her first child, so they are moving there now. Her vampire brother in law is very excited about the move, as he is a Fire Chief and citizens of Twinbrook sometimes look at him funny when he arrives to the emergency sparkling like a human disco ball...
I've never played any custom worlds apart from the ones from Store. I did like the general aesthetic of Midnight Hollow, but I honestly couldn't stand the lighting in there, it just felt far too depressing for me, even though I understand that it fits the town well. Sometimes I just want to have a nice Spring/Summer sunshine that doesn't make everything look grey, I think even serial killers and psychos deserve that :)