Self-isolation is the most painless and painful condition that can lead to the fact that you can only sink and not move forward
A shot in the back of the head. I think the most humane and painless kind of execution. A person will die quickly enough and there will be no such thing that he will have to listen to the screams and other sufferings of a person (even if he is at least a serial killer, because what happened has already happened)
Shooting is the most painless. I think that when a bullet hits the head, instant death. The most painful execution will be hunger in a punishment cell without water.
This is when, first, sodium thiopental is injected into a vein and the brain is turned off, removing pain, then muscle relaxants are injected so that the convict does not twitch and, finally, a large dose of potassium chloride, which stops the heart. The sentenced person lies like a log, the doctor can only wait 10 minutes and state the death of the sentenced person. This, in my opinion, is the most humane way of taking life, and for witnesses too. All others are painful and not aesthetic.