I am very... narrow minded when it comes to sci-fi. I love the Iain M. Banks "Culture" novels. Where people see changing sex as a part of life. If you haven't read those, you really should. I have never been a huge sci-fi person, though. I prefer High Fantasy. Tolkien, Gemmell, those kinds of writers. I feel like it's very hard to world build a good sci fi series. Very few people get it right, most people get it wrong.