1.weed
2.DXM (fuck you, i took 500+mg and had a great time)
3.Betel nut
4.Ambien
5.Valium
6.Genista canariensis (a kind of scotch broom)
7.alcohol
8.any anticholinergic, they make you feel like shit (i think i may have also lost some important memories.
i'm certain that when i get my hands on a psychedelic it will rank as #1.