I was once a virtually 100% non-fiction reader, but once I got done with school and had more time for discretionary reading, I made an effort to read more fiction. As of late, I’ve actually been sticking to a semi-rigid schedule of reading 2 non-fiction then 2 fiction books (with fiction further subdivided vaguely into “high highfalutin’ literature” and “popular”) which seems to be working pretty well with my wandering interests.
I think a lot of it is that I’ve gotten a lot better at choosing good fiction. With non-fiction, even if it’s poorly written, I usually feel like I learned something. I was exposed to a lot of bad (or at least personally uninteresting) fiction during my formative reading years, but with so many good resources available now (not the least of which being book recommendation threads here), it’s a lot easier to find fiction that doesn’t leave me feeling like I wasted my time.