I happened to glance at the back of the DVD cover for my copy of Trainspotting and was very amused to read the following:
The motion picture sensation that wowed critics and audiences nationwide, Trainspotting delivers a wild mix of rebellious action and wicked humor! It's the story of four friends as they try to make it in the world on their own terms...and who end up planning the ultimate scam! Powered by an outstanding cast of rising young stars (including Emma's Ewan McGregor) and a high-energy soundtrack, Trainspotting is spectacular, groundbreaking entertainment.
Compare this to the much more accurate (if somewhat pretentious) plot summary from IMDB:
A wild, freeform, Rabelaisian trip through the darkest recesses of Edinburgh low-life, focusing on Mark Renton and his attempt to give up his heroin habit, and how the latter affects his relationship with family and friends: Sean Connery wannabe Sick Boy, dimbulb Spud, psycho Begbie, 14-year-old girlfriend Diane, and clean-cut athlete Tommy, who's never touched drugs but can't help being curious about them...