Shotgun and explosives look amazing, do you know if there's anything under 1 second (agony). The Titan implosion was like several 0.000001x10 milliseconds fast, they didn't even know they were dead, I wonder if there's a similar method that's much easier to acquire. All I can think of is certain anesthesia drugs and having someone kill you in your sleep after you lose consciousness.
Though I prefer a much more independent method, there's too much risk trying to involve other people in my plans.