fictional futures

I'm going to be on just one panel at Readercon, but it's a fun one:

Our panelists will discuss the fictional futures they find most appealing and would be happy to live in (maybe with some caveats). Does the work that depicts these futures provide a path or hints as to how humans might get there? What makes these futures worth rooting for and aspiring to?

I have some thoughts on the topic, but what I also have is a question:

What books have you read that are set in appealing futures? What books...