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.
Iain M. Banks' Culture series of course. Player of Games is the best starting point, though Surface Detail is my favorite.
Adrian Tchaikovsky's Children of Time series is as close as I've ever seen hard sf get to the Star Trek IDIC ethos.
Kim Stanley Robinson's Mars trilogy is good near future ecology and politics focused sf.