Trying to name your top 12 films is an almost impossible task so I've set a much easier one. Just name some German films that you've enjoyed. No top fives or top tens as you may have only ever seen one and liked it. So name as many or as few as you like. Mine include:
Mephisto
M
Fitzcarraldo (one of my favourite ever films)
The Tin Drum
Wings of Desire
The Lives of Others
I think you have to otherwise most art would be consigned to the dustbin.
Another vote for Das Boot here. Masterful suspense.
Not exactly a film, but Channel 4's Deutschland 83 of a couple of year's back was a Major (Tom) Must-Watch
Funny Games is excellent. The Hollywood balls up of a remake should not put you off.
I just remembered another - Europa, Europa - the real life story of a Jew who joined the German army. I actually saw it in Germany, in the city were a good part of the film was set. I recall looking around the audience at the 50 or 60 year-olds there (this was 1990) and wondered what they'd been doing during the war.
kleines arschloch
Das boot
Downfall
Die welle