Here is my list, depending on the mood:
Stoner Comedy Classics:
- Up in Smoke (Cheech & Chong)
- Half Baked
- How High
- Harold & Kumar
Stoner Classics:
- Dazed and Confused
- Fear and Loathing in Las Vegas
- The Big Lebowski
- Human Traffic
- (2001 - A Space Odyssey)
Absurd Comedies:
- Airplane
- Napoleon Dynamite
- Hod Rod
- Tenacious D in The Pick of Destiny
- Anything by Monty Python for example Life of Brian
- Barb and Star go to Vista Del Mar
Visually Trippy Movies:
- Beach Bum
- A Scanner Darly
- Waking Life
- Glossary of Broken Dreams
Trippy & Weird Movies:
- Sorry to Bother You
- Sans Soleil
- The Holy Mountain
- Bakara
Drug Movies (trippy but not recommended if you are looking for a good time):
- Enter the Void
- Requiem for a Dream
- Trainspotting
- Spun (this one at least is still a comedy)
Edit: Bonus mention Dark Side of The Rainbow, that is Pink Floyd’s Dark Side of the Moon synced to The Wizard of Oz
Event Horizon was vastly underrated. Also, I learned the other day there was a scene that was removed due to being so disturbing but the footage was stored poorly and became so degraded we will never get to see it. Which only makes my imagination run wild.