define 'most psychedelic'
in its literal sense, 'mind revealing,' well from the RCs ive sampled they dont compare to something like DMT, LSAs/Morning Glory Seeds, Mushrooms, or LSD. Ive found the RCs are less entheogenic than their more traditional counterparts.
But if you just wanna trip out, then the 2C-T-xx drugs, as jamaica mentioned above, have given me the most powerful visuals ive ever had, except for DMT (although DMT isnt really 'visual' more like 'visionary'). Ive never tried 2C-E or 2C-I, but I hear they arent profoundly visual. 5-MeO-DiPT was never strongly visual to me, and AMT had weak visuals at best. The 5-Meo-DiPT experiences I had left me absolutely engrossed with patterns, seeing movements within stationary objects, and obsessed with checking out carpets up and close, however, the visuals I got from 2-C-T-7 were the most intense visuals ive had without being in a state of ego loss.