Reading classic books can boost your learning experience. There are some reasons why classic books can do that: they have stood the test of time, they give you different “lenses” to look through, and they will most likely be relevant even to the far future. Reading the classics is an excellent intellectual exercise which will arm you with a lot of powerful intellectual tools.
To find good classic books, there are trusted recommendations that can help us. The recommendations are found in the books How to Read a Book by Mortimer J. Adler and Charles van Doren, and The Well-Educated Mind by Susan Wise Bauer, both of which I believe are high-quality books. You can read the books for complete information about their recommendations (with suggestions on how to read them), but here I will directly give you the titles of the books which are recommended by both of them.
While I believe a book which is recommended by any of them is good, I think it’s safe to say that a book which is recommended by both of them is great.