Stoner movies can be hard to define, but you just kind of know one when you see one.

For example: The mere presence of marijuana, does not a stoner film make.

It reunitesPineapple ExpressdirectorDavid Gordon Greenwith starsDanny McBrideandJames Franco, so ‘nuff said.

420 Films

Credit: Everett Collection (3)

18.Dude, Where’s My Car?

Or, obviously, where they parked their car.

Plus,Method ManandMary-Kate Olsencostar, lending it their stamp of approval.

Paul Rudd and Emily Mortimer

Nicole Rivelli

Most excellent, indeed.

Come to think of it,Super Troopersshould probably be higher on the list.

9.Knocked Up(2007)

Seth Rogen’s slacker father-to-be inKnocked Upnever had a choice.

The movie is set in middle ages and the marijuana is called wizard weed, but it’s also a Pineapple Express special, featuring the director along

Frank Connor

Happens all the time.

Oh, and they learn some important life lessons.

Stoner movies don’t get much more creative than that.

Dude, Where’s My Car? | Nine years before The Hangover , two stoners (Ashton Kutcher and Seann William Scott) wake up one morning with no recollection of the previous night.

Tracy Bennett

Happens all the time, or, at least, it happens inHow High.

Fear and Loathing in Las Vegas | Marijuana takes a back seat to mescaline and LSD in this bitchin’ Hunter S. Thompson trip, but Raoul Duke (Johnny Depp) and Dr. Gonzo (Benicio

Peter Mountain/mptvimages.com

Clerks | Shameless reprobate Jay (Jason Mewes) and sage Silent Bob (Kevin Smith) eventually became immortalized in comic book form as Blunt Man and Chronic, but in

Miramax

The Wackness | This coming of age film set in 1994 Manhattan tells the story of a lovesick teen (Josh Peck) who deals weed from his water-ice cart

JoJo Whilden/SPC

Alex Winter, Keanu Reeves, … | This dumb-buddy vision quest enabled the existence of Dude, Where’s My Car? and was made by the director who brought us Harold & Kumar Go

Everett Collection

DAVE GROHL, Tenacious D in the Pick of Destiny Only a rock star could channel the appropriate level of hedonistic delight when playing the Prince

Peter Iovino

Fast Times at Ridgemont High, Sean Penn | Jeff Spicoli, Fast Times at Ridgemont High Long before Sean Penn was the go-to guy for Oscar-baiting gravitas, he was Spicoli: a surfer dude who’s

Everett Collection

Reefer Madness (Movie - 1936) | Ostensibly a terrifying cautionary tale about the dangers of marijuana-induced psychosis (with a poster that’s become a dorm-room classic); really more like Our Town on

Everett Collection

Joey Kern, Jay Chandrasekhar, … | A highway-patrol pot caper involving a bear costume, syrup-drinking contests, and an Afghan cartoon monkey carrying coded Taliban messages. Come to think of it, this

Fox Searchlight

Knocked Up, Jonah Hill, … | Seth Rogen’s slacker father-to-be never had a choice. His name is Ben Stone, and his juvenile housemates and even his dad (Harold Ramis) are chronic

Suzanne Hanover

Cheech & Chong, Cheech & Chong’s Up in Smoke | Cheech and Chong bring their doobie-brothers act to the big screen, at one point illegally crossing the border in a van made entirely of reefer.

The Kobal Collection/WireImage.com

Half Baked, Dave Chappelle, … | A rainbow coalition of celebrity cameos populates this whacked-out film that’s sort of about Dave Chappelle dealing stolen medical marijuana and sort of about Jon

Everett Collection

Ice Cube, Chris Tucker, … | On Friday, with nothing to do, Ice Cube and Chris Tucker get high, sit on a porch, and watch the ghetto go by. Oh, and

Everett Collection

John Cho, Kal Penn, … | A pair of pals (Kal Penn and John Cho) quest for tiny burger bundles of joy. Their totally baked journey includes a stop at Princeton

Sophie Giraud

How High, Method Man, … | Method and Red smoke weed planted in the ashes of a dead friend, and his ghost gets them into Harvard. Happens all the time.

Sam Urdank

Pineapple Express | In what might be the only stoner action movie, two unlikely doobie brothers, process server Dale (Seth Rogen) and groovy dealer Saul (James Franco), bond

Darren Michaels

Jeff Bridges, The Big Lebowski | The Dude (Jeff Bridges) is the greatest stoner in the history of film because the Dude abides, dude.

Merrick Morton

Matthew McConaughey, Dazed And Confused | Richard Linklater’s slacker opus glides along on a buzz stoked by Aerosmith and carefree youth. You don’t need to have a joint to hang with

Dazed and Confused: Gramercy Pictures/Everett Collection