Comment by Adlai

First, the one mentioned in the parent:

  https://www.erowid.org/experiences/exp.php?ID=26033

And a couple skimmed off the all-time best[1]:

  https://www.erowid.org/experiences/exp.php?ID=31722 (Nitrous Oxide)
  https://www.erowid.org/experiences/exp.php?ID=17787 (Mushrooms)
  https://www.erowid.org/experiences/exp.php?ID=104336 (Ibogaine)
  https://www.erowid.org/experiences/exp.php?ID=96838 (Methoxetamine)
  https://www.erowid.org/experiences/exp.php?ID=68367 (Sensory Deprivation)

Obligatory honorary mention:

  https://www.erowid.org/experiences/exp.php?ID=68111

[1] - It occurred to me that I selected predominantly positive, or at least 'wonderous', reports. Dig around and you'll find some that are less so.