What are some really good books that help learning the Spanish language?

I am already fluent in Spanish, but I lack the comprehension of common slang, and common phrases that one would hear living in a Spanish speaking world. Are there any good books for this? Please do not tell me about 501 verbs in Spanish or some Spanish dictionary, I would like titles of books that tells the "real" Spanish that is spoken outside of grammar texts produced in the United States.