Big fan. Passion de Jeanne d'Arc is an all-time favorite.
Look up Victor Sjostrom's work, he is perhaps the most accomplished director of the silent era. Terje Vigen (released for English speaking audiences as 'A Man There was') is perhaps my favorite. The Phantom Carriage was groundbreaking, and The Wind was surprisingly good.
If you like Dryer (who did Passion of Joan of Arc), another good silent work of his was Vampyr. Surreal and Lovecraftian, but not nihilistic.
Most good silent films are not American, I've noticed.