Of all the films American master David Fincher has made, Fight Club remains the hardest to watch. It's a violent (still shockingly so), punk-rock thriller, a purveyor of the darkest comedy that seeks to laugh at your lot as a working stiff and assure you of one thing more than anything: that your life is absolutely meaningless. So why do people continue to return to the film some 16 years after it was released (yes, it really has been that long)? Well, for one thing it's a spectacularly shot, edited and paced film, featuring some iconic performances and line upon line of memorable dialogue, much of it lifted straight from Chuck Palahniuk's blistering source novel. More important to the film's longevity, though, is that it's a movie aching with ideas - about identity, about contemporary living, about what it means to be a man - that stands to be scrutinised for decades still to come. The film has its detractors, but even those who dislike Fight Club can't argue that it's one of the most fascinating there's been in the last 20 years of cinema. For anyone new to Fight Club but keen to explore some of the themes found in the film, be warned - spoilers follow throughout.