If you're being honest with yourself, you know you're really not going to want to go to a country where you would have to completely learn another language. I am skeptical when somebody has something like Iceland or Korea as a top pick.
England
Canada
Austrailia
New Zealand
Sweden
Essentially my perspective as well. I'd like to learn another language, but presuming the current state of affairs in which I haven't, this would be my list.
Climate is an issue for me. I'm in Pennsylvania and wouldn't want to live anywhere colder...but conditions in America are making Canada, for example, look awfully cozy by comparison. Multiculturalism and a good social safety net are high priorities that override my hatred of snow.