The plot is that these guys are getting high a lot and crazy shit happens to them. Its pretty crazy.
This is a standard stoner adventure comedy, which have a tendency to pop up every like 5 years and cause everyone I know to wet their pants over how fresh the humor is, even though its pretty much the same hat as the last stoner movie. Examples would be Harold and Kumar coming out 5 years ago, and Half Baked coming out 5 years before that.
The movie is actually pretty funny, if you arn't bothered by the positive portrayal of characters that use weed, which seems to actually be a problem for some since the imdb board are filled with anti-marijuana threads, but I still find it odd how fresh and new the movie fells when its just like every single stoner movie put out since Cheech and Chong got in the game.
He's in this.
Craig Robinson should be in more movies.
Still, the movie feels fresh, despite how much it really isn't, and I think a lot of it has to do with the budget for the movie. While Harold and Kumar always felt like a Dvd hit, and Half Baked was always a Comedy Central movie, because that's where we all saw it, don't lie like you went to the theater to see it, this movie feels like an actually... um, movie movie. And people actually saw it in the movie movie theater. So because of that, you get the feeling like, "hey, its a real movie with the stoner mentality" unlike Harold and Kumar or Half Baked, which don't count, because they aren't real movies, and I think that's where I was disappointed a bit.
The movie always sold itself as a action/thriller type outing but with all the funny craziness of a stoner movie added to it, kinda like if your favorite action movie lighted up and took itself less serious. It really isn't, but you watch it thinking it is, never noticing that its pretty much Cheech and Chong with Seth Rogan and the guy from Spiderman that plays Harry Osborn in it, and you say, "that was like nothing I've ever seen before wow!" By the time you actually reflect on it, its too late because you can't take that shit back!
The movie gets its name from weed. The movie is all about smoking weed
In the end Pineapple Express is the the most unique breath of fresh air type movie you will ever see because we all know what a big stoner you are and how terrible your memory is. Its hilarious and it has the guy from Spiderman that plays Harry Fucking Osborn in it, so don't even act like it doesn't. Your just being a jerk here.