Since I have posted this thread I have almost completed Jared Diamond's Guns, Germs and Steel and The Mote into God's Eye by Jerry Pournelle and Larry Niven, which are incredible books. Since I am devouring them your recommendations will soon find their way into my Kindle.
If you like Larry Niven, you might also like Vernor Vinge... A Fire Upon the Deep (bk1) and A Deepness in the Sky (bk2).
As a fellow Game of Thrones (Song of Ice and Fire) fan, I'll recommend a couple of my other favorite fantasy series. Both are similar to GoT in some ways - well developed characters and worlds, and more of an alternate medieval setting rather than the old standard Middle Earth clone (elves, dwarves, wizards, and halflings out to stop the dark lord).
First Law Trilogy, by Joe Abercrombie. Great characters and story. Lots of action, but pretty dark (and bloody).
Farseer Trilogy, by Robin Hobb. Characters are very interesting and complex... because of the amount of time spent on the characters, it is a bit slow paced compared to GoT and First Law. Not at all boring though. It's a great story, and I really enjoyed it. It continues with the Liveship trilogy and then more Farseer books.