I generally have dirty old men try to tell me their whole life story, and no amount of ignoring or inching away completely rids me of 'em. Usually when I'm, say, waiting to board or for a bus, so I can't just leave the area.
Luckly I've never ended up next to one on a flight. The weirdest there was probably just a kooky hippy lady.
Heh...I had one of those type men sitting beside me on the subway in DC. Asking all kinds of personal questions, which my mom happily answered for me including my last name which she very thoughtfully spelled out for the fellow.