All drugs should be legal.
The bottom line is you own your body, and have a right to decide what to put in it, regardless of what damage it does to you. If you decide you want to swallow a large amount of bleach, that is up to you. When government tell you that you can not consume a drug, they are basically claiming that they have more rights over your body than you do, they are essentially claiming ownership of you like a slave.
The same applies to euthanasia, prostitution, or any other instance were the government forbids you from doing something with your own body. It is like outlawing food or masturbation, the government simply has no right, and any time they attempt to enforce such a law, they should be treated as hostile oppressors, and fought on the matter.
If drugs cause you to break other laws or cause you to act in a negative way, then those behaviors should be illegal, not the substance, as this leads to people using the drug as an excuse to justify their behavior.
I smoked weed for over 11 years, not once did I have to steal anything or hurt anyone because of it.
Furthermore, prohibition did not work with boxing, alcohol, or anything else they have tried. By outlawing it all they are doing is pushing the activity underground, and putting money in to the hands of serious criminals. If you can’t keep drugs out of a super maximum security prison in the middle of a desert, then there is just no hope of stopping it in the streets.
People who are against drugs are not going to start using drugs just because it is legal, sure, a few new people would perhaps try them, but so what, their body, their choice.