If, when you think of sci-fi art, the first thing that comes to mind is astronaut babes in spandex and fishbowl headgear fighting giant gourds, you really need to update your expertise. Some of the sci-fi art from the 70s to today is among the most visionary and mindblowing surrealism yet created. Actually, for me, the stuff reached a sort of high point in the 70s.
But there are still some modern masters working today. Stephan Martiniere has worked on a number of big projects, from great books to the recent Star Wars films. His work is technically proficient, aesthetically fascinating, and imaginative beyond belief. His works can be viewed here.