It would have to depend on the weapon that was to be used. I don't think I could pysically go up to someone, with a knife, or rope to strangle or stab them, not only because I'm a pretty pysically weak person (LOL) but it makes it seem more real.
If I were to get back at someone, and actually had the balls to do it, then I would use a gun, it's the whole thought of "hunting" a person down, the mentally strong VS. the mentally weak.
I reckon I could become a hitman actually, that would be fun