I'd say legalize most of them. What adults put into their own bodies is mostly their own business. Educate everyone on the dangers of drugs (including cigarettes), and put some of the money that currently goes into the drug war and put it into rehab centers. Some should still be illegal to sell on the street (only can be sold by a licensed center, who will recommend rehab for customers who are buying too often), but otherwise should be legal to possess and use.
Also release all prisoners currently in prison for drug possession, unless convicted of another crime.
Also release all prisoners currently in prison for drug possession, unless convicted of another crime.