What is the most slow painful and most agonising way to die?

i would think drowning or burning or dieing from heat exhaustion.

Being de-headed but still be alive and your nerves are still active in your head.

Answer:I would have to say being placed in a containment cell under ground and having your mouth welded to a pipe that works as a septic system. Your capture can keep you alive though urine (water base), and feces which you could survive on for sometime. When death does come it will be of starvation or because you've consumed to much and the stomach line tears filling your body with waste and causing infection.... Lol so yeah.......