Psychedelic trance music artists

All-time psy trance classics definitely include:
1. Oga Syndicate's "Argon"
2. Robert Miles' "Endless"
3. DWFS "Initial Gain"
4. Juno Reactor's "Feel The Universe" (plus, about half of the rest of the album Beyond The Infinite that this track comes from is pretty good psy)

Of all these, Argon is the prototypical psy-trance track. It has all the elements of excellent EDM: strong use of both analog and synthetic instrumentation; danceability; and mixability. Psy-wise, it's got the goods there, too: wide soundscape; duality of a slower melody behind the immediately catchy phrases; and lots of echo!

I actually like Initial Gain more but Argon is more prototypical of what psy trance is today whereas Initial Gain is a throwback track. Trance used to sound more like Initial Gain before the mid-90s, before commercial trance:

Juno Reactor is always associated with techno above all, but their techno was very atmospheric, so some of their stuff sounds quite psy (back when they first broke on the scene techno still sounded very interesting and was very diverse in tempos and themes. Today's techno pretty much sounds more like house music made by people too lazy to program an all-synth melodic hook, but before techno turned into today's crap a lot of early trance sounded like early techno, and this is the reason why I recommend you get the whole Beyond The Infinite album; the album betrays strong psy notes).