I'm looking for books like the title - a realistic but hopeful depiction of the future. Mostly interested in near future, building after the revolution type stuff, but I'd be open to more outright utopian sci-fi as long as the worldbuilding was interesting.
The Culture of course
Ken MacLeod's Fall Revolution sequence (TROTS IN SPAAAAACCE!). And several of his other books.
The Commonweal by Graydon Saunders (though this is fantasy) The revolution against the god mages ended 400 years ago, it is still too early to see if the only free society for 300'000 years is viable.
There's also the Soviet written Solar Union series, of which Hard to be a God is part