Arlanda feels like another good example of a "far out" (23 mi) airport that works pretty damn well. 18 minutes on the train.
It really blew my mind when I first visited, I never thought getting to a major international airport could be that convenient. Swiss transit is so well designed.
Metro and commuter trains run all day and all night (the trains also go to Malmø in Sweden).
Long distance trains go all the way across Denmark and as far as Gothenburg in Sweden, although there are very few been midnight at 4am.