Here's a classic: Ringworldby Larry Niven, the 3rd Novel to win both the Hugo and the Nebula awards (there have been a few more since).
I feel that the ‘Hard SF’ tag is rather undeserved, but consider this tale of strange aliens, unfathomable artefacts, and the rise and fall (mainly the latter) of galactic races and civilizations highly entertaining. ‘Wizard Of Oz in Space’, was what came to mind...
Louis Wu is celebrating his birthday with a huge party. But, given that it is his 200th birthday, he feels 24 hours are not long enough, and at midnight he embarks on a trip around the world, from town to town, always ahead of the new day, to extent his Bicentenary as long as possible. During one of these jumps his Transfer Booth is tampered with, by Nessus, a Puppeteer, who want to hire him for a top secret mission.
