Greatwinter trilogy by Sean McMullen. Quite enjoyable, but not really space type scifi
https://www.goodreads.com/book/show/..._Great_Machine
The Day of the Triffids along with its two sequels - The Age of the Triffids and The Night of the Triffids (the better sequel)
The Book of Ember...
https://www.goodreads.com/series/40332-book-of-ember
Flood and Ark, both by Stephen Baxter
And Blade Runner and its three sequels which, in my opinion were not that great.
Hmmm, I'm also thinking of The Host, but not sure if it is Utopian or Dystopian. Depends on your viewpoint - overrun by symbiotic aliens (dystopian) but brought peace and enlightenment to the world (utopian).