I believe that you have put forth both a difficult and easy question to answer.
First, let us examine the word "deviation". In one definition, the word deviation means:
departure from an established ideology or party line; noticeable or marked departure from accepted norms of behavior.
Therefore, many texts fall under the first definition. To explain, each new literary period that emerged tended to be a stand taken against the previous period. For example, the Romantic period came about as a reaction to the Age of Reason. The Age of Reason was/is characterized by authors whom thought it was their duty to tell readers what to think (mostly in regards to the Revolutionary War). The period was all about creating common thought regarding societal and private issues.
In reaction to the Age of Reason, the Romantic period bloomed. Instead of telling readers what to think, the Romantics wanted their readers to feel something about their work. Basically, the Romantics valued feeling over that of reasoning. Characteristically, Romantics' texts were filled with imagery of nature and imagination.
Therefore, any work that proceeded a previous period would be a deviation to the movement of literature. To give a distinct example, Mary Shelley's Frankenstein deviates greatly from Thomas Paine's The Age of Reason.
More more difficult part of the definition to contend with in regards to literature is "noticeable or marked departure from accepted norms of behavior." While the previous does so, I tend to regard this definition as deviating from what is accepted as a literary society.
I believe that any text could be justifiably deviant. If a reader does not agree with the stand, the material, the religious tone, or the sexual orientation of a character they could deem the text deviant. Therefore, it would be very hard to define specific texts as deviant without a standard by which to deem the text deviant.
For example, many people do not agree with the material presented in J. D. Salinger's The Catcher in the Rye. The book has been, and still is, banned in many schools. The obscene language and sexuality of the novel was deviant to many. I, and my students, would have to disagree.
To close, it is very hard to create a permanent line in the ground to which one could place deviant texts on one side and non-deviant texts on the other. The term "deviant" is simply to subjective.
The second link provides a website where you can look at books which have been banned (or are still banned) and why they are considered "deviant".