I adore love can not rave enough about Harry Harrisions Eden Trilogy.
http://en.wikipedia.org/wiki/West_of_Eden
"advanced society primarily based on a mastery of the biological sciences, especially genetic engineering"
It is the only books I have ever jumped up and down over. Not a castle in sight. I have never been a fantasy reader tho I am now into Game Of Thrones. But these books are just amazing. I have told everybody I know into sci fi and fantasy and they all loved them. I have no idea why they are not more popular.
applesauce