I'm a big Piers Anthony fan. His Xanth series is very light fantasy. I prefer the Apprentic Adept series, which is a combination of sci-fi and fantasy. The first book in that series is titled <i>Split Infinity.</i>
I also like his Incarnations of Immortality series. The first book in that series is <i> On A Pale Horse. </i>
For straight Sci-Fi, he has the Bio of a Space Tyrant series, beginning with <i>Refugee.</i>
He also has single books, both sci-fi, fantasy, or a combination of both. I have almost all his books.