Well, I must show my filmic ignorance here as I haven't seen a whole of of silent movies (although plenty B&W ones). I'm seen a few Chaplin, Keaton & Laurel and Hardy movies which have stood the test of time well, but on the whole, I find them hard to watch as its film-making from a different era with very exaggerated facial expressions and movements.
Plus, sharp dialogue is one of the things I look for in movies, so Silent films aren't what I'm after!
