Just as a demonstration: 

1 Film: 1900 - 1910 
2 Films: 1910 - 1920 
21 Films: 1920 - 1930 
17 Films: 1930 - 1940 (no film after 1935, btw.) 
9 Films: 1940 - 1950 
10 Films: 1950 - 1960 
10 Films: 1960 - 1970 (ridiculous - the 60ies were SO !!! important, not only for German Cinema) 
16 Films: 1970 - 1980 
11 Films: 1980 - 1990 

Nothing after 1990... there were some REALLY significant films up to 1995... 

Many silents are lost but still, there were not nearly as many films produced than later in the century. 
From the 50ies to the late 80ies, Germany had an enormous output, nearly as big as Italy's or Japan's. 
What does significant mean? According to this list, the more social critical, society critical and history based a film is, the more significant it is. Bah. It's childish. 
According to this list, only films that received international success (which means: were awarded and appreciated by critics) are significant. 
According to this list, films that deal with unpleasant, controversial themes can never be really significant. 
According to this list, only " good" (= serious for the sake of being serious) or non-commercial films are significant. What about films like "Jud Süß / Jew Süss", "Zu neuen Ufern", "Liebe kann wie Gift sein", "The Third Sex", "Different from the Others", "The Fellowship of the Frog", "The Dead Woman of Beverly Hills", "Schoolgirl's Report", "Es" or "The Treasure of Silver Lake", "Deadlock", the films of Rosa von Praunheim, "Nekromantik", "Die Jungfrauenmaschine", "Schramm", "Der Fan", etc., etc., etc.?!!?!!?!!?!?!?!?!?!?! 

@ arsaib: 

Well, I considered that. I love many, many films from this list, btw. But to include films like "Der Himmel über Berlin" or "Die Drei von der Tankstelle" is just... ridiculous. Or "Die Abenteuer des Baron Münchhausen" - Just because it was probably the most expensive (and, as far as I know, only coloured) German film from the 40ies? I beg that wasn't meant to be totally serious. (Such) A film by Joseph von Baky...! I mean... doesn't "significant" mean outstanding, revolting, influential, innovative, inventing, unique, superior, remarkable...?! 

By the way, there are also many films on the list which are practically unknown and almost never shown here. Critics, Filmmakers and Editors also have their own taste and, of course, they are big buddies with institutions like Die Deutsche Kinemathek. 

My complain isn't so much about the films on the list but more about the films which are NOT on the list. I'm sure, half of the films from the 20ies and the 30ies are just on it because they are from the 20ies and the 30ies which are considered to be the most significant decades of German cinema today by all those idiots mediocre talkers and writers who call themselves professors, critics, insiders, film- and media scientists or whatever. Sorry for being so striking but the German cinema with all of its faces, shadows, tranformations and its beauty has a very warm place near to my heart (it's a phrase, I know) and I was offended personally a bit. You know, I tend to take things a bit too personal...