Well, you've got your epic fantasy, and your personable... Dan Simmons (Hyperion saga, Olympus), Rameez Naam's "Nexus". Nick Harkaway's "Gnomon" is ridiculousl

Well, you've got your epic fantasy, and your personable... Dan Simmons (Hyperion saga, Olympus), Rameez Naam's "Nexus". Nick Harkaway's "Gnomon" is ridiculously good, and I basically buy anyone who wants one a copy of Cory Doctorow's "Walkway". Theodore Sturgeon is probably the closest SF I can think of to Pratchett, although he's Golden Era so suuuuper soft SF and doesn't have the humor. Bujold's "Vorkosigan" saga is one of the funnier SF books (while still being amazing and serious), and I hear good things about Scalzi's "Redshirts" PS - Also checkout out what Hannu and Rameez get up to outside of writing, it's super cool.