David and Leigh Eddings. The Belgariad, Malloread and the expanded universe is criminally underrated and absolutely worthy to be compared to Tolkien and Pratchet's works.
Not ashamed to admit I haven't exactly read an awful lot of fiction but from the ones I did and stuck with me I gotta say Bernard Werber and Michael Crichton are the names I grew up with. I'm now in the middle of exploring Bruce Sterling's work which managed to catch my attention.