What do you mean by "classics" of literature? A Handbook to Literature (Holmon and Harman) defines a classic as "a piece of literature that by common consent has achieved a recognized superior status in literary history; also an author of similar standing." (from Holman, C. Hugh and William Harmon. A Handbook to Literature. 6th ed. New York: Macmillan Publishing Co., 1992.)
The phrase "by common consent" is the tricky part here; not everyone agrees on what the classics are. But lots of people have created lists of what they believe to be the most important books. Below is a list of some of the books that our library considers as classics. And you can read them online!
[Online eBooks courtesy: Project Gutenberg]