In any stealth game, when I'm sneaking about, I'll never talk, always whisper, the guards might hear me. I've done this since halo:CE. I also have this odd urge to kill the guards I'm supposed to sneak by. There's this little itty bitty voice telling me of all their wrong deeds they have done, and how its justice that I kill them. I also try and justify myself for killing civilians in GTA IV. Like I shoot a guy in the head as he drives by, saying that he cheated on his wife. Or killing people hiding in alleys, because they deal drugs.
Also, I have this tendacy to always try to look badass. For example, in Fable II, I was goign good all the way, but while wearing the assasin coat, and bandit clothes, with black hair, and the evil facial hair. Becasue I looked freaking epic. Same thing with Fallout three. Instead of the the better armor, I choose what looks cool.
And I guess I must name pokemon ironic nicknames. For example, gloom is always nicknamed despair. Either that or scruffy. My entire team was called scruffy in diamond version.