Well Das Boot made it to theaters back in the days. It did get nominated for 6 Oscars. lol.
As for Das Undertag, I think it won the Oscar for best foreign film. It wasn't long in theaters here in North America though. I was lucky enough to find a place where they were playing it. It's not in English, but you can just see the acting is amazing by the way it's played out, emotions and all. Prob one of my faves.
Also, last one I can think of that I saw recently is The Counterfeiters, came out in 2007. I think it was made in Austria though... Either way, it's about how Jews were used to made counterfeit money which was practically perfect to the point where they'd be making British Pounds used to exchange money to make the Reich richer.