You wake up from cryogenic sleep in a medical bunker underground. The Earth is dead after the final war, first nuked, then radiated, then burned to a sterile crisp. You're not just the last member of Homo Sapiens Sapiens, you're the last biological life form on the planet, full stop. All you have is a bunch of robots of limited AI capabilities designed to Serve Man, your memories, and a cryogenic chamber that can let you sleep for thousands of years at a time if you want. What do you do? Go.

I read this a loooooong time ago and something about it always stuck. Finally managed to find it again and yes, I like it. Sure it's aged a bit, especially technology-wise, but the AI aspect is still pretty clever, and for being basically the inverse of Stapledon's First and Last Men (or a precursor of The Martian with no hope of actual rescue) it holds up. What's man to do but play god, and what's his creation to do but outgrow him?