Some time ago in this same forum a thread arose asking for everyone's top 5 psychoactives (http://www.dmt-nexus.me/forum/default.aspx?g=posts&t=4991). As is common in this type of threads, no results or insights are present in the end. Well, having some analytical background and wanting to discern a pattern, I picked up the 18 meaningful answers and used a very simple methodology to get a synthesis.

Of course very different approaches might be followed, but this one provided fast and reasonable results. Here's the basics (you can skip this and go directly to the final table if you want!)
a) As 5 substances were asked I assumed a scoring system according to the order. Thus, 1st place 5 points, 2nd place 4 points, and so on until last place 1 point. 15 points at all were distributed per answer
b) In some cases the answer stated there was no specific order, then I attributed 3 points to each substance.
c) In some cases people put more than one substance in one place.For such situations I divided the results so that I always got distributed 15 points as correctly as possible
d) Two answers corrected their previous answers in the thread. I only counted the last answer.
e) I grouped some substances where I thought were appropriate (cactus and mescaline) yet separated smoked spice from ayahuasca, as I believe the nature of those 2 latter experiences is completely different
f) In the end I summed all the points and attributed a relative score to each substance (in %) presented below

And this all I remember now. More questions, please do ask, or suggest a better methodology! These are the results above 3%

Substance %
DMT 17.7
mushrooms 14.3
cactus/mescaline 13.4
ayahuasca 11.9
cannabis 8.7
LSD 7.0
bufotenine 4.7
Smoked Salvia 4.0
Others (*) 18.3

(*) LSA/LSH, kratom, kava, 5-meo-dmt, ibogaine, 2C-*, GHB, etc

I was not surprised to see DMT at the top (this is the nexus after all!), I was perhaps a little perplexed with the good results of mushrooms and cactus. The difference to DMT is not too large, specially for a forum biased to DMT. Bufotenine on the top, also made me wonder. And of course, cannabis above LSD. This may have to be with the reduced availability of the latter product, but several answers clearly mentioned cannabis above LSD. A clear surprise.

These are results which are of course valid only for this forum and have a wide error margin (18 answers is clearly too few). But it is better than nothing and the results presented an interesting picture on usage and preferences.

Hope this is not too off topic for this forum and of interest to some of you

Not too surprised there really. It's nice to see that they're all relatively safe substances too

... not that expected crack and meth to be in there mind.

The first 4 of them all have the same psychedelic potential. All 4 of them can take you to the same place. In the right amounts they have more or less the same effects. There are some differences.

Smoked DMT is the most intimidating of them.
Ayahuasca is less intimidating than pure DMT, but both have a very deep psychological impact.
Shrooms in large amounts are equal to DMT and ayahuasca in almost every way (check the 'did you ever had a breakthrough on shrooms?' thread if you don't want to take just my word for it), but they have less psychological impact and are for that reason also less intimidating.
Mescaline is the least intimidating of them all, but still gives a deep psychological trip. It is visually less colourfull than the others but has more synesthestetic effects and gives more feelings of wellbeing.

All other psychedelic substances i know (i have no experience with salvia and bufotenin) are inferiour to the 4 mentioned.
They are THE ultimate psychedelic substances.

^^ I agree. I dont have as much experience with aya as I do with mushrooms. Both have brought me to my knees kissing the ground I walk on..but I think the vine really speaks with her own voice, really soft but with the most clarity..will be interesting to see how mushrooms are with the vine.

Smoked DMT I am finding more and more to blast straight to the core of my being, but leaves alot quicker..
Cactus I have the least experience with but it helped me cope with a bad situation with my old roommate and my best friend so it's invaluable..mescaline is so warm and inviting I dont know how anyone could hate it...and my last experience with it showed me that it has quite the visionary power as well.

Salvia is up there for me as well..but she's differnt. She doesn't do the work that the others do. Someone on here said that DMT was the sun and mushrooms, aya, LSD and salvia were the planets that orbit around it..but I dont think that comparison is just..salvia is another universe unto itself..salvia would have it's own list..

Bufo I like alot, but so far its the best combined with DMT for me, so I dunno yet..

Top 3 for healing everyone though I would say are Ayahuasca, mushrooms and cacti..in no particular order.

If I had only 4 right now it would be those 3 plus salvia...