Marijuana is already legal in California, Oregon, Washington and Colorado. But, I hate this drug. It has highly variable and unpredictable effects on people. It cause me: 1) extreme panic attacks, 2) paranoia, 3) extreme anxiety and a general sense of being unwell. And, that horrible drug lasts forever and seems to take 3 days to wear off. About half the people experience the same effect, and the other half love it. I have no idea why. It’s a very weird drug. Plus, it has no effect on you when you first take it. It’s like an SSRI drug (anti-depressant). It takes about a week of daily use for its effects to even be felt. 

Just chiming in to second what SHL said about marijuana.  The very few (I think two) times I really smoked the stuff (as opposed to 'not inhaling' like Mr Clinton) I ended up a quivering, terrified wreck!  On the other hand, I know people with chronic pain who love the stuff and seem to remain normal while smoking it daily, so it's obviously very individual.

Personally, I'd never touch anything that gave me a risk of seeing things that weren't there; and I saw a picture of Daniella Westbrook's* cocaine-wrecked nose at a young, impressionable age so nothing is going up my nose, either.  Those two criteria rule most illegal drugs out!

*A British soap actress who was a cocaine addict.