As a German, the thing I like most is that you never ever see bottle trash lying around in parks or on the street, as any stray bottle is quickly (and I mean within minutes) swept up by the homeless/less fortunate.
One of many things that impressed me in Germany.
Homeless people pick up the beer bottles, and cola cans, but they won't collect the wine bottles, or the packaging from the snacks, but Danes seem to leave this in the park with the bottles.