Depends if I've killed my doppleganger yet. I've never met him, but I know he's out there, watching me. There is nothing that makes me more nervous than the fact that I'll have confront him one day, and at that moment, neither of us will hesitate. But I suppose I wouldn't feel so bad if I lost to him. I imagine the rain starts pouring down on me as he holds me in his arms and watches the blood drain from my body and the life from my eyes with a sort of melancholy you can only feel from knowing you had no choice but to kill the one person in this world who could truly understand you, and yet whose life you had no choice but to end. Or maybe he just smashes a photocopier on my head repeatedly and puts the result on a Christmas card to my loved ones. I haven't quite figured out yet which one of us is evil.
Other than that, I'm partial to being a bystander in a gang/police shootout or something. I never knew what hit me, but I don't mind, it seems like they have a lot of money on the line.