Here is Mental Floss' 25 Most Powerful Books of the Past 25 Years, based on societal influence, not on publishing records.
It's a well-researched list, and the magazine offers detailed rationales for each book. Number 6, Ehrenreich's Nickle and Dimed, for example, helped lead Congress to raising the minimum wage in 2008.
The Washington Post didn't entirely agree, but it's an interesting list to consider.
1. And The Band Played On (1987) Randy Shilts
2. Maus (1991) Art Speigelman
3. Listening to Prozac (1993) Peter D. Kramer
4. Thinking in Pictures (1995) Temple Grandin
5. Nickle and Dimed (2001) Barbara Ehrenreich
6. Into Thin Air (1997) Jon Krakauer
7. The Satanic Verses (1988) Salman Rushdie
8. Middlesex (2002) Jeffrey Eugenides
9. The Alchemist (1988) Paolo Coelho
10. The Easy Way to Stop Smoking (1985) Allen Carr
11. A Perfect Spy (1986) John Le Carre
12. What is the What (2006) Dave Eggers
13. On Writing (2000) Stephen King
14. The Wind-Up Bird Chronicle (1994)
15. The Known World (2003) Edward P. Jones
16. Harry Potter and the Sorcerer's Stone (1998) JK Rowling
17. How Proust Can Change Your Life (1997) Alain de Botton
18. The Bonfire of the Vanities (1987) Tom Wolfe
19. Infinite Jest (1996) David Foster Wallace
20. The Unbearable Lightness of Being (1984) Milan Kundera
21. Beloved (1987) Toni Morrison
22. The Handmaid's Tale (1985) Margaret Atwood
23. Freakonomics (2005) Stephen Levitt and Stephen J. Dubner
24. Eats, Shoots & Leaves (2003) Lynne Truss
25. The Tipping Point (2000) Malcolm Gladwell
And in case you need a bit of levity in your life, here's Bert and Ernie's take on gansta rap. I can't really understand what they're saying, but it's highly entertaining. Enjoy!