My sci-fi novel Star Chosen just climbed to #31 in the top Bestselling eBooks on Amazon under "Christian science fiction"
What I think makes a science fiction novel great must include the following: Conflict and resolution in a futuristic setting that opens areas of the reader's mind to new and useful insights. It's one of the goals I was aiming for when writing the Star Chosen book.
To order this novel, go to the Star Chosen product page: http://joechiappetta.blogspot.com/2010/03/buy-book-now-star-chosen-science.html