** spoiler alert ** Some books are that good. They are parodied, recycled, passed over, and come back again with a resonance in the world of storytelling that few ever equal. Of Mice and Men by John Steinbeck is a masterwork of literature with its themes of love, regret, friendship, honor and the knowledge that all things in this world pass. If you have never read this book then I cannot call you a true lover of literature.

Summary
George and Lennie are migrant farmhands, traveling the barren world with little to call their own. George, the small and intelligent one, has secured them work at a farm where they can begin to collect wages that will someday allow them to buy their own place. Lennie, the large and childlike one, dreams of having their own place where they will "live off of the fat of the lan'" and where he will get to tend the rabbits.
The two find comfort in the farm with Lennie proving his exceptional physical labor skills and a new partner in their endevor, Candy. Daily life in the worker's clubhouse is shown, especially in one scene where the men convince Candy to kill his beloved, elderly dog.
The comfort is short, however, when the hot headed owner's son, Curley, picks a fight with Lennie and ends up with Lennie crushing Curley's hand. Another form of trouble comes in the form of Curley's wife who feels she is too good for the life she has chosen and often hangs too close to the workers.
The climax comes when Lennie accidentally kills Curley's wife and George, knowing Curley will kill his friend, has to end Lennie's life.

The Good
What can I say that has not been said about this book? The characters, plot, dialog, setting, language, etc. are all perfectly balanced to tell a simple story about the desperation of man.

The Bad
The only bad aspect of this novel is its simplicity. This is not a detriment to the story, but to everyone who must see the plot and characters parodied for all eternity.

Why is it banned?
Of Mice and Men could be banned for a few reasons. The language is often both racist and misogynistic towards Crooks, the elderly black man in the story, and Curley's wife respectively.
The violence, while not gratuitous, could also be a reason, as the story depicts a dog being shot, a woman being murdered, and a man being executed with a shot to the head. The scene where the men encourage Candy to put the dog down could be seen as inciting violence toward animals, particularly elderly ones. Combined with the misogyny of the earlier language, the murder of Curley's wife could also be seen as an attack on women as well.
Some may be disappointed with the depiction of Lennie as a mentally disabled person, as well. While his childlike attitude is forgivable, the violence he exhibits is not and may lead some to the wrong conclusions.