I can't tell you how often I think things are funny and no one else does. Uncomfortable silences I find very funny. Things in threes with a pause and an accompanying fourth. Jokes about death. Science jokes. Puns. Tumbleweeds. '_____ walks into a bar' jokes. Flat punch line delivery. Anything that sounds dirty but isn't. Anything dirty. Clearing of the throat in quiet situations. Inadvertant rhythms. Ricky Gervais. Embelishments. Enmelishment. Exagerations. And of course the 'When someone is lifting something heavy and says "can I get a hand" and someone else (usually me) applauds' gag. Holy shit, that never gets old. Never, never, never.