It's hard to recommend a book for someone else if you don't know that someone else. I take it he likes sci fi, you don't, so you want help picking a book for him?
If it were ME -- I'd rather be asked what books I'm interested in. He'll know what he wants and hasn't yet read. How would you know that what we recommend isn't a book he hasn't already read?
Also, a lot of folks like EITHER sci fi OR fantasy.