I’d say that the three books — each actually a series of books — that have had an impact on me are:

J.R.R. Tolkien’s “The Hobbit” and “The Lord of the Rings” trilogy

Why? These books totally transported me to a fantasy world from very long ago and far way.

James Clavell’s “Shogun” and “Tai Pan”

Why? These two books totally transported me to a land from long ago and far away.

Isaac Asimov’s “Foundation Trilogy

Why: This series of books (and others in the “Foundation” series) totally transported me to worlds far into the future and very far away.