Re: Charles Stross suggests that neighbors are ISIS-like and abhorrent
He's also contributed at least two more scenarios:
"Saturn's Children" / "Neptune's brood". Our successors are AIs which we created as our slaves. We then go extinct (as slave-owning societies always have done in the past, on a non-global scale). They're out there, colonizing the galaxy and trying to reincarnate homo sapiens (from DNA codes, with a degree of success), for quasi-religious reasons!
Accellerando, in which human beings are supplanted by evolved digital corporations which no longer need to preserve their human customers. These denizens of "Economics 2+" turn the entire solar system into computronium (solar-powed computing substrate) and don't travel, because they always seek the most bandwidth-rich environment, ie nearest to Sol.
The first pair of books are amusing and less implausible than most interstellar SF. Accellerando will haunt your imagination. Both recommended.