In one sentence: misogynistic twaddle.
Now let me say straight up, I am not one who puritanically hates violence in entertainment; a hallmark of a great film is violence used effectively in the service of character, comedy or horror. I DO have a problem with 'men can only take back their masculinity from evil modern women's equality by BEATING THE CRAP OUT OF EACH OTHER.' It feeds into this whole bullshit theory (that feminists are equally guilty of defending) that men have an innate NEED for violence, that their manhood is inherently tied up with brutality.
That said, I have a general disdain for any story that has a main theme of 'men being emasculated.' Again, the whole concept means there is a clearly defined version of what being a male means, and a feeling of emasculation usually reflects some form of misogny. This misogyny is further reflected by the fact that while the movie tells of the man-destroying feminization of the world, there is only one female character, and that female character is a balls-out male fantasy, ill equipped to challenge the movie's main point (though at least she doesn't confirm it).
This sort of surface deep analysis of social issues is rampant in the film. Now that we've got wussification of men out of the way, lets attack consumerism! In the stupidest, most idiotic, 'I wanna be a Red Army Faction Black Shirt but without any political ideology' kind of way. Back-fat soap is the instrument of horror, but like everything else in this movie, it's cheap and shallow.
Fight Club also commits the ultimate crime in fiction of any form; the illegitimate twist ending. An ending that completely removes the validity of the entire world the audience has been subjected to, an ending that exists only because the writer cannot be bothered to come up with something better.
WOMAN ON THE AGORA
I thought I was alone in hating this movie, but here are some of my more legitimate (employed!) brethren on the film:
Roger Ebert (Chicago Sun-Times): "
Fight Club" is the most frankly and cheerfully fascist big-star movie since "Death Wish," a celebration of violence in which the heroes write themselves a license to drink, smoke, screw and beat one another up."
Peter Bradshaw (The Guardian):
"But, by the end, it has unravelled catastrophically into a strident, shallow, pretentious bore with a "twist" ending that doesn't work. And it is a film which smugly flirts, oh-so-very-controversially, with some of the intellectual and cultural paraphernalia of fascism - but does not have anything like the nerve, still less the cerebral equipment, to back this pose up."
And my personal favorite, by Lisa Schwarzbaum (Entertainment Weekly):
"The giant international furnishings chain IKEA is responsible for many consumer-based phenomena, among them our docile acceptance of cheap, hinged desk lamps that droop like spent lilies. But I hadn't realized that overexposure to IKEA results in limp penises, too, until I saw Fight Club. David Fincher's dumb and brutal shock show of a movie floats the winky, idiotic premise that a modern-day onslaught of girly pop-cultural destinations (including but not limited to IKEA, support groups, and the whole Starbucks-Gap-khakis brand-name axis) has resulted in a generation of spongy young men unable to express themselves as fully erect males. And that the swiftest remedy for the malaise lies in freely and mutually beating the crap out of each other -- bleeding, oozing, cracking, and groaning until pulped bodies crumple to the floor in a poetically lit heap." 
