It is hard to choose a favorite.
Comedies:
Chaplin, Keaton, Laurel & Hardy, Keystone Cops so many others.
Dramas
Metropolis, Nosferatu, Das Cabinet des Dr, Caligari
To call these German Silent Films just doesn't sound right.
How about Silent Films from Germany?
There is also the first film (and the last film) to win an Academy Award for "Artistic Quality of Production" Sunrise: A Song of Two Humans
Wings
The sad thing about most of the films from the silent era is that they no longer exist.