I don't think total legalization is the way to go. Drugs like cocaine, meth, heroin, crack cocaine, Ecstasy, and many others are actually very harmful both physically and mentally, and the addiction for them is a hard thing to break, and stay away from once you're clean, especially if they were legal.
Marijuana should be legal since it is no more harmful than alcohol and cigarettes (hell some claim smoking pot is less harmful than cigarettes but until it's legal we can't test it and say for fact.)