Iain M. Banks, The Player of Games

John Varley, Steel Beach

Roger Zelazny, Lord of Light

Zachary Mason, Void Star

Dave Duncan, Hero!

Jeremy Robert Johnson, Skullcrack City

3 Body Problem

The Years of Rice & Salt by Kim Stanley Robinson. Epic alternate history novel beginning in the 1300s.

Rendezvous with Rama by Arthur C Clarke. A contained & very exciting adventure on a mysterious alien spacecraft. Classic SF.

Check out the front runners for a Hugo award this year:

Book of the New Sun. You're not gonna regret it.

Journey to the center of the earth from Julio Verne

I strongly recommend Ancillary Justice and the other books by Ann Leckie set in the same universe.

Asimov - Nightfall & Other Stories is probably the best short story collection I've read, if you're into that.