An American comes to realize after a while....that certain American topics....will not fly on German TV very much.
So this is a list of sorts for the non-flyers.
UFOs. There just isn't much of a group in Germany who puts any faith or belief in UFOs. Privately, I'd even take a humble guess that barely five percent of the population has some serious belief in them. So you don't see many UFO reports....UFO movies....alien stories....or such. For a German, there has to be some serious drama and reality tied to such a story, with absolute facts. Without that? It just won't be seen or discussed.
Cult stuff. It's generally hard in German society to start up a cult. I'd be the first to admit that there's a fairly long list of acceptance factors you need to meet before you get any attention as a 'new' religion or such in Germany. Just recruiting down in some city square....will get you odd looks....and if you were able to convince one guy out of a thousand....you'd be lucky.
Ghosts. Ghost movies will play on German TV but beyond that? Forget it. Unlike the British who run tours in ghost-inhabited castles....the Germans tend to keep their old castles in a condition without ghosts.
Buried treasure. On rare occasions....you come across some German guy who found some Roman coins or some buried Nazi-era loot. It's exceptionally rare and Germans don't usually buy into the buried treasure routine very well.
End-of-times predictions. About every year in the US....some figure or group is running up the end-of-times prediction flag. Sometimes....millions are drawn into the discussion....until the mythical day arrives, and things just keep on going. Germans aren't much into the end-of-times stuff. It's hard to convince them that taxes are coming to an end.....that snow won't happen anymore.....or that the local pub won't be open Saturday night.
Germans kind of demand some facts before they run off on some behavior change. It's hard to sell a German on fake stuff.....without proof.