(What, Already done. Damn)
Lord of the rings
(Again!)
Dune!
(No don't tell me.)
(I have go to get out more!)
Ok. How about The Lensmen books by E.E. "Doc" Smith?
Stainless steel rat would also be good.
The Wizardry compiled. By Rick Cook. (A book that all computer programmers would love) (Also available on line Here
or The "Camber" series by Katherine Kutrz (or the Deryni books that go with them)