I personally find Buster Keaton a much more expressive actor than Charlie Chaplin. Sure, he maintains a poker face but his slight frown and sad eyes are enough to generate enormous empathy, as opposed to Chaplain, who hides behind his mustache and bowler hat, as well as his almost dehumanizing 'tramp' persona. Yes, it's a cute tramp. But Keaton's hapless, yet normal, guy is, I think, more sympathetic, and much more current. Keaton's silent films are notable for their extremely sparing use of on-screen dialogue, his wit is very visual.