Rat poison is NOT a good idea, as I’ve heard it’s an extremely painful way to go.
Gunshot to the temple is also not a sure-fire (forgive the pun) method. I knew of a fellow that tried that. The bullet ricocheted off of his skull, and basically just followed the curvature of the skull inside 'round, and 'round until it lost momentum, and stopped on TOP of his brain, rather than inside. He ended up a semi-vegetable, aware of his surroundings enough to realize the state he was in, but not aware enough to function normally. Pretty horrifying.
Assasinating a dictator isn’t all that great of an idea, either. You might get shot, but you also might recover, get arrested, and be placed in a third-world country’s prison, awaiting execution. They also might torture you to get the names of your accomplices, and wouldn’t you be screwed, not having any?
I can’t imagine that a Bungee cord would be all that effective, due to its elastic nature. I don’t think that you would snap your neck cleanly once you reached the end of the cord, else Bungee jumpers would always be breaking their ankles when they jump. Seems to me that you would just recoil a few times and then slowly strangle.
Carbon monoxide is effective, and painless, but what about the others that might enter the home and be accidently poisoned by the gas? Your pets?
Drugs and wrist slitting might not be effective, and take too long. Somone might rescue you before you died, and if you’ve taken enough drugs, you might end up a vegetable.
I also don’t fancy the idea of any of my loved ones finding my body, or having a nasty mess to clean up.