@Clwojick - this is a super tough question & so I had to add a sixth, but here‘s what I‘d say today (in no particular order):
1. Hitchhiker‘s Guide To The Galaxy by Douglas Adams
2. The Belgariad series by David Eddings
3. The Complete Sherlock Holmes by Conan Arthur Doyle
4. Name of the Wind by Patrick Rothfuss
5. A Prayer For Owen Meany by John Irving
6. Pride & Prejudice by Jane Austen