I have couple stories of being intimidated. Most of them revolve around elementary schoolers that act exremely professional (ei: "rating?" the tiny Indian asks, then nonchalantly nudges his glasses).
I've also had cases of extreme time awareness, like where my opponent just slaps my hand and hits the clock as fast as possible (on game 90 +30 second interval) when the TD says "shake hands and begin." I'm not sure if that's intimidating or not, but it does offer a psychological distraction. Whenever you can get your opponent thinking about something other than the game, you just decreased his strength.
But my eariler examples are silly examples; most TDs would kick someone out if they were being overly disturbing to others.
I watched my first tournament for a bit a few weeks ago. I noticed that everybody was staring at the board avoiding face contact with the opponent. Some people wore noise cancelling headphones too. So....its not that hard for your opponent to just ignore you.
I notice in videos of which GMs are playing, that they occasionally glance quickly at thier opponent or smile when they know they have won. Do you have a story of a case of intimidation that worked or went wrong..lol.