I’ve heard that autoerotic asphyxiation isn’t a bad way to off oneself. Worked for Michael Hutchence.
As for ODing on painkillers: Vicodin contains two active ingredients, acetaminophen (aka Tylenol®) dihydrocodeinone (aka hydrocodone). The problem is that the acetaminophen is extremely toxic when taken in quantity. 10 grams of acetaminophen taken at once will basically turn your liver into a bloody sponge inside of 24 hours — an agonizing death by inches instead of a painless fade-away.
The drug that causes death in lethal injection executions (sodium thiopethal aka Sodium Pentothal®) will, when given intravenously along with pancuronium bromide and potassium chloride, produce unconsciousness followed by a painless death within ten minutes or so.
:X YUCK!