I would say Psy-Trance or Goa. I listen to what people consider "psychedelic" rock from the 60's and forward but NOTHING has ever made me tripping like PsyTrance or Goa. Nothing from Beatles, nor Pink Floyd nor Jefferson Airplane etc. Don't get me wrong - I listen to classic/hard/psychedelic rock more often than to anything electronic, but when I want really psychedelic, trance-inducing stuff that will make me jump crazily like a monkey while being in a deep trance and sometimes even without alcohol or ganja (I haven't smoked weed since 2008!! and I have never taken any other drug), I go for psytrance, sometimes Goa. BUT I have never had LSD, therefore maybe I cannot properly judge what is psychedelic (I don't think so, as I have had many psychedelic experiences on psytrance parties, with the help of only alcohol or weed). The difference between those two is that Goa is an older genre, but still being made (see Suntrip records for example). Goa is based on melodies and layers of various electronic instruments creating harmonies and crazily flowing and twisting and twirling err...melodies... and taking you to an endless trip into the universe and so on...while psytrance is less organic and melodic and more technical and "sci-fi"-like, I would say based on hard-hitting rhythms and more straightforward melodies. There are of course many subgenres of psytrance, some are dark, fast with few or no melodies at all, based on crazy psychedelic sounds and echoes and other effects; while others are more melodic, with 1/16 notes as a bassline and some stuff on it etc. My favorite subgenres of psytrance are South African psytrance, which somehow blends darker sound with some great acid melodies and sounds; and the British stuff from labels like Wild Things Records, Last Possible Solution or Ambivalent Records - especially Wild Things put out some extremely psychedelic (IMO) stuff that makes me go crazy very very easily and quickly... For example try to listen to track "Mutiny" from EVP on youtube, which is from his album "Holographic Consciousness", that's some ********* crazy s**t! All that album is excellent but this track is the best. Also check out stuff from Realitygrid. THAT is psychedelia in its purest form IMO. All this is my opinion of course and there are millions of people who would have vastly different opinions, I'm sure. However - I have some friends who "would never listen to any electronic music" and after being brought to a psytrance party rarely listened to anything else than psytrance. And I'm not a fan of mainstream electronic dance music. I listen to drum and bass sometimes but that's it. I don't like commercial house, trance nor techno, I HATE that stupid thing called "dubstep" and I extremely loathe electro, and I think that all that mainstream (electronic or non-electronic) music, especially modern pop and stuff like that completely lacks any soul or idea. Psytrance and Goa give me something that no other genres could - go and visit some psytrance parties and you will understand what I mean. Still, when I want the best "listening pleasure", I put on my HD650's and play some The Who, Beatles, AC/DC, Buffalo Springfield, CCR, Hendrix, Steppenwolf, The Band; or some more contemporary artists like Nirvana, Smashing Pumpkins, Foo Fighters, Soundgarden, (old) Radiohead, U2, REM; or yet, when I'm in the mood something harder like Metallica, Machine Head or Deftones. And all of those I just mentioned can be quite psychedelic also, but I have never experienced such state of trance and cosmic visions in my head like when listening to quality pystrance.
For anyone interested (if there's anyone), here is a list of my favorite Goa/Psy-Trance artists:
Man with No Name
Hallucinogen (Simon Postford, a real legend, not much goa, more like old-school PsyTrance/PsyTechno IMO, later involved in some great more ambient/chillout/dub stuff, like Younger Brother or Shpongle, both VERY GOOD)
and many more...
Afgin (most of his music is available legally for free on www.ektoplazm.com
, contains a lot of uplifting, sometimes slightly "cheesy" melodies, I like his music very much!)
and many more...
Brethren (older stuff, newer stuff is not very good IMO)
and many more...
I could go on and talk about Psychedelic Trance all day really but this sums it up. There's also a lot of important stuff I forgot to mention but I think ^^^this represents my opinion on this subject nicely.
Have a nice day and - of course - don't take it too seriously