how has nobody suggested The Fifth Imperium or the Baen free library yet?
http://baencd.thefifthimperium.com/
http://www.baen.com/library/
there's enough free sci-fi and fantasy there to choke a horse. I'm partial to David Webers Honor Harrington series but theres enough there to keep you reading for the rest of your life. And its all free and legal.