Sometimes I run the way the Assassin from Diablo 2 does. Other times I'll use the phrase "roll a _________ check" when something happens. And I occasionally say "Spah's sappin' mah internet," when my bandwidth reaches its cap and reverts to dial-up speed, or if my sister's playing a Facebook game. They use up so damn much... makes me want to log on to her desktop and block the site somehow, just to see how she reacts to going without it for a week. Hell, even a day.
Anyway, there's heaps more. I quote the Team Fortress characters when I speak, the hood of my hoodie always reminds me of Altair or Ezio when I wear it, I have a set of clothes that make me look kind of like a Pokemon trainer... the list goes on.