Science Fiction/Fantasy is not a genre I tend to lean towards, so you probably won't find many recommendations here other than for my friend, Chris Greenway's series of books!
Sometimes an author writes with such talent that you just know you'll buy their next book, no matter what the subject. You go looking for their books, and when you find them, you squeal! These are those authors.
Note: When Chris is published, you'll find him here! :-)