i like nitrous for the
minute it lasts...
i like DXM, its not quite as euphoric as ketamine or PCP, but it has a unique psychedelic and mild empathogen effect that the others don't have(DXM is a potent non-selective serotonin reuptake inhibitor, so that may be why). plus its OTC :D.
PCP is euphoric, but definitely the biggest "mindfuck" compared to ketamine or DXM. it also is stimulating even at doses that cause strong dissociation so i'm able to wander around in a mindstate similar to a k-hole, which often leads to me doing stupid shit or acting in a bizarre manner. when i smoke dust i stay at the lower end of the dosing scale, its just a bit unpredictable.
ketamine i'd say is the best. its euphoric, lasts rather shortly, and feels "cleaner" or "smoother" than the others(even in a k-hole). it can be addictive as hell though.