AH! I've got one now! Hitman blood money and Hitman 2, I always felt bad if i had to kill cops, after all, they do not know who they're dealing with. They're in WAY over their heads, and simply don't stand a chance. Sometimes i'm even on their side but explaining that is simply not a possibility.
Then you get those "innocent" people, particularly in hitman 2, but then some of them will have guns and at that point they're not all that innocent, are they? But most of them didn't need to die, they were just in the wrong place at the wrong time. After all, i can't really let them live after they've seen me.