I have some (personal and from others) recommendations for you:
Childhood's End, The City and the Stars, 2001: A Space Odyssey, Rendezvous with Rama by Arthur C. Clarke, It by Stephen King, Vorkosigan Saga by Lois McMaster Bujold, Hyperion by Dan Simmons, Dune by Frank Herbert, City by Clifford Simak
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Off-Topic