To live in: Beorn's realm/house. I want to live here soooooooooo badly. Mountains, valley, meadows, streams and ponds, fabulous house, tons of animals and a garden. Nobody else nearby. Quiet. I would be very very happy here.
To visit on holiday: Rivendell and Erebor.
I wouldn't want to live in Rivendell or Erebor, but I would love to visit them every now and then. Both are magnificent and beautiful in different ways. I would like to see Erebor both in its colorful heydey, and also post-Smaug. Cuz, really, who doesn't want to run and play and slide on a mountain of gold coins?