Absurdist fiction, according to wikipedia, is a genre of literature, most often employed in novels, plays or poems, that focuses on the experiences of characters in a situation where they cannot find any inherent purpose in life, most often represented by ultimately meaningless actions and events. Common elements in absurdist fiction include satire, dark humour, incongruity, the abasement of reason, and controversy regarding the philosophical condition of being "nothing." Works of absurdist fiction often explore agnostic or nihilistic topics.
While a great deal of absurdist fiction may be humorous or irrational in nature, the hallmark of the genre is neither comedy nor nonsense, but rather, the study of human behavior under circumstances (whether realistic or fantastical) that appear to be purposeless and philosophically absurd. Absurdist fiction posits little judgment about characters or their actions; that task is left to the reader. Also, the "moral" of the story is generally not explicit, and the themes or characters' realizations—if any —are often ambiguous in nature. Additionally, unlike many other forms of fiction, absurdist works will not necessarily have a traditional plot structure (i.e., rising action, climax, falling action, etc.).
The absurdist genre grew out of the modernist literature of the late 19th and early 20th century in direct opposition to the Victorian literature which was prominent just prior to this period. It was largely influenced by the existentialist and nihilist movements in philosophy and the Dada and surrealist movements in art. - End Wikipedia quote. Many great works of literature, in my personal opinion, have been modeled off of the Absurdist philosophy in one form or another. Some popular works that include some elements of the absurd are: Alice in Wonderland, Through the Looking Glass, 1984, Animal Farm, Cat's Cradle, The Metamorphosis, Catch-22, The American Dream, and The Illuminatus Trilogy.