12 book series that are the sci-fi equivalent of A Game of Thrones

Wondering what to do while you're waiting for the rest of George R.R. Martin's saga?

We've got nearly a year to wait until the fourth season of Game of Thrones hits HBO, and who knows how long until the sixth book in Martin's A Song of Ice and Fire series is released, so we have to do something to fill the void. And over at Reddit, a lot of people offered their suggestions on exactly what, from which we've culled a dozen of the best. Obviously there are loads of other brilliant epic fantasy series out there to devour, but what if you want a change of pace? What if you'd like to trade in those castles for space stations, or those other realms for other planets?

Luckily for all of us, there are plenty of great sci-fi sagas out there that feature the same themes, intricate worldbuilding and adult tone that we love in A Song of Ice and Fire. Sometimes these novels will give you vast universes encompassing dozens or even hundreds of planets, and even more unique characters. Sometimes they'll give you the horrors of war, sometimes dark moral ambiguity, sometimes even dragons (oh yes, sci-fi can play the dragon game too). So, if you love Game of Thrones but you'd like a little bit of a sci-fi shift in your reading life, check out any one of these 12 series from some of sci-fi's finest authors.