First off, This movie is one of the great movies out there that I suggest everybody should watch. The movie is obviously based around drugs, Marijuana to be exact, and it also does an excellent job of not putting marijuana down or advertising it. The trailer shows your two typical pot smokers going about their life, until one witnesses a murder and you get the idea that they are running for their lives. This is somewhat the case, Although they do a great job at putting a twist to the story that most people probably wouldn't see coming. The movie is located on youtube, Although I don't want to post any of the links in case the mods ban me for it.
The beginning of the movie starts out with Dale Denton (Played by Seth Rogen), who goes around giving legal notices to people while saying the generic catch-line, "You've been served". Dale is like your average American citizen who happens to enjoy a few joints while on the job and also has a highschool girlfriend (18 Years old, Plays a slight part in the movie). About ten minutes into the movie you are then introduced to Dale's drug dealer, Saul (Played by James Franco).
From the beginning you can tell Saul is lonely, since he's trying to prove how happy he is and prepping up his place while Dale just wants to buy some weed. Saul introduces a new strain called Pineapple Express and sells some to Dale. Near the end of the day, Dale is smoking a pineapple express joint and witnesses a murder, Fearing for his life he drops the roach and runs. A cop and a man in a suit walks out and the man finds the roach confirming that it's pineapple express. Dale arrives at Saul's apartment and after telling his story the two panic and decide to make a run for it. Of course thing's don't go planned and well, You'll have to watch the movie to find the rest.
Overall, I'd have to say this movie is a must see and if you are looking for a good comedy then you should definitely watch this.