GDR, the country that was usually just called East Germany, has not the best reputation when it comes to film making. Heavy handed, class conscious propaganda pieces rather come to mind than fun, realism or emotional honesty. This list is supposed to bring the other films back to attention - the truthful look at Germany's Nazi past, the playful children's movie, the social reportage from society's centre. Most films were made in the state-owned film studio DEFA, located in Potsdam-Babelsberg near Berlin, but there were other film studios, too.
A valuable, english-friendly source of information is the blog East German Cinema that covers a lot of the films listed here - and more.