This should be moved, but I'll speak while I'm here.
I saw about the last half hour of City Lights, and it was impressive. I preferred what I saw of Modern Times and The Gold Rush, and yes, The Great Dictator (I saw these three in their entirity), but I can't comment fully until I see City Lights fully.
However, I must say that I prefer the work of Buster Keaton and Harold Lloyd over Charlie Chaplin, who, although very poignant, is perhaps a little overrated. Keaton was droller and Lloyd had that everyman appeal.
As for which film is superior...although there are a few handfuls of films, at the very least, that are in my mind superior to Raiders of the Lost Ark, Chaplin is probably not among them. Other masters, such as Ford, Wilder, Kubrick, and Lean, to name just 4, would be.