I'm suprised noone has mentioned any of the OTC stuff like DXM, DPT and DPH... These drugs I personally see as being deleriants/dissociatives, but it appears that many people on this forum concider them to be psychedelics, and if so how is DPH not the worst, end of story. It makes you feel like you're about to die, the majority major hallicunations have to do with shadow people (which is just bloody scary at most times) and you tend to pass out on the peak. DXM I can see as having potential as a really good introspective trip, but i've been on 4th plataue a couple of times after sculling 3 or so bottles of the rotten stuff and although it was intense, cheap and available easily, it isn't really 'enjoyable' if you know what I mean. I mainly only do it when I can't get my hands on something better and need to communicate with my higher conciousness, but then I have mates who hold it as their drug of choice and would rather take it then Mushrooms and other, what I beleive to be more 'wholesome' psychedelics.
Anyway, my 2 cents.