Your question is hard for me to answer at this point in my life. There was a time I would not have finished reading the question and my answer would already have been meth. It's not that I thought I wouldn't do it if I had the chance, I did not think the opportunity would ever come to me. I thought my world and that world were too far apart to ever cross. And then they did and this is the best answer I can give to your question.
Addiction is not limited to alcohol, tobacco, opiates, and stimulants. Addiction is any habit so powerful that to abstain causes mental and physical turmoil, driving the user to continue to use at the expensive of their best interests. In other words continuing to use as the punishments for doing go become more and more severe.
For that reason, I think weed is the worst for people who are addicts to get away with using, as well as allowing them to feel superior to the rest of us addicts.
Cocaine is the worst for efficiency. It is so Dan expensive for such a short high. I would go through the entire gram bag in one go, I paid $100 for the gram, and the high was gone 30 to 45 minutes. It was a decent high but not for what I paid and how much I needed to do to get to it. It was not a tolerance issue, I have done coke 4 times.
Crack I have not tried but I was told more than once in treatment that coming down from crack is the worst. Crack is the worst in ways I don't know how to explain.
Adderral is the worst because it is socially acceptable meth.
Meth is the worst because an angry tweaker is the most dangerous person on the planet, It doesn't matter who that person is off of meth. Meth is the worst for the soul, whether or not the tweaker ever becomes Devil level angry.
Heroin and opiates are the worst because they are the best at taking your life. It is not uncommon for an overdose victim to become angry and even aggressive towards the person who revived them. The overdose high is what everyone is chasing. An overdose is the best thing that can happen if it happened to someone using your product. The narcan ended the high, there is a chance that person is heated.