I'd have to tie LSD and 2ce. To be fair though, I haven't done a huge variety of substances, at least not to the extent that a lot of people here have (only done p. cubensis, p. cyanascens (I consider these two "separate" psychedelic experiences because the character of each was so wildly different), LSD, 2c-e, 2c-i, 2c-d, salvia, dxm, MDA, mescaline and morning glories)
LSD and 2ce both provided amazing visuals and musical enhancement. On the one hand, LSD has the slight upperhand when it comes to bodyload because it has none for me - but 2ce's was very negligible, even when insufflated, as long as I took DPH.
but on the other hand, I thought the quality of 2ce's visuals were superior.
they tie on music enhancement, because they each enhanced it in different ways. LSD made the music more omnipresent, intense, and distorted... whereas 2ce created a cooler "flanging" effect (classical piano, each note sounded like you ramped up the flanger on a synthesizer!), and made each sound INCREDIBLY sharp and clear. I heard the most subtle noises, such as coughing and foot moving and pedaling (in classical piano) from the studio on 2ce. incredible.