Books that I recommend.
(Spiritual and religious purposely omitted)

• Adams, Douglas: "The Hitchhiker's Guide to the Galaxy" series, and "Dirk Gently's Holistic Detective Agency"
• Asimov, Isaac: "Foundation" series.
• Brooks, Terry: "Magic Kingdom for Sale (Sold)" and "Shannara" series.
• Card, Orson Scott: "Ender's" series.
• Cooper, Louise: "Chaos and Order" series.
• Donaldson, Stephen R.: "The Chronicles of Thomas Covenant the Unbeliever" & "Mordant's Need"
• Eddings, David: "The Belgariad" (5), "The Malloreon" (5), "The Elenium" (3), "The Tamuli" (3).
• Feist, Raymond E.: Riftwar, Empire, Serpentwar series (all Midkemia/Kelewan books).
• Goodkind, Terry: "The Sword of Truth" series. (~4,500 pages and climbing) These are outstanding!
• Harris, Debra & Kurtz, Katherine: "The Adept" series.
• Harrison, Harry: "The Stainless Steel Rat" series.
• Heinlein, Robert: "Stranger in a Strange Land"
• Herbert, Frank: "Dune" the first set of three are mandatory, the second set, optional.
• Hickman, Tracy & Weis, Margaret: "Chronicles" trilogy & "Legends" trilogy and Knaak, Richard's "The Legend of Huma"
• Jordan, Robert: "The Wheel of Time" series (~8,000 pages and climbing)
• LeGuin, Ursula K.: "Earthsea" trilogy.
• Martin, George R. R.: "The Song of Fire and Ice" series.
• Rawn, Melainie: "Dragon Prince" trilogy "Dragon Star" trilogy.
• Tolkein, J.R.R: "The Simarillion" & "The Lord of the Rings"