Which book is better for my dad? He likes science fiction novels.?

Out of those Michael Crichton books, the only one I've read is Eaters of the Dead, and I thought it was pretty good. I've often wondered about the Andromeda Strain, though... If I were to recommend any sci-fi book that I've read, I would probably say Dune, by Frank Herbert... It's goes a little into politics, which is never as exciting, but I really enjoyed it. The second one in the series, Dune Messiah, was pretty good too, but after that they just got weird.