Depending on temperament, I suggest LSD. Set aside 8 hrs you
  won't need. Get ready for specialfx. I've tried a bunch (just
  the 'classics' I suppose) and that was the only one that was
  worthwhile for the trouble. I'd stay away from opiates and
  derivitives because they're physically addictive. I don't think
  many of the others are physically addictive, unless you count
  nicotine - which *really* is addictive too. Crack I tried twice.
  Crack was strange: I liked it and initially had the strong want
  for more (for about 4 hrs) but after that, nothing except for
  one peculiar thing: For 10 years afterwards, I could TASTE it
  right in the back of my throat just thinking about it. I can
  describe it: a burnt sweet plastic taste... but I can't taste it
  anymore. I'd smell it from far away. I didn't feel compelled to
  have any - just a weird taste-memory. It's gone completely now
  though. But 10 years... man. Long time. And the 8 hrs for LSD?
  That's 4 hours of fun and 4 hours of, "ok, I REALLY want to go
  to sleep now...this is annoying". = There would be though. The
  difference is who is pocketing the profit. Many will have their
  hands out for it. It would have to be strictly laid out and
  negotiated between numerous parties for it even to be
  considered, especially in very large countries like the USA. The
  price point would have to be comparable to current black-market
  prices otherwise they wouldn't have much impact on current
  procedures. == Alas, our planet is full of humans. I don't know
  if such a thing is possible, except perhaps in small
  communities. [the 150-or-less rule: anything over 150 ppl and
  it's difficult to maintain a hierarchy-free subculture] ==