I vote for James Patterson. His books used to be awesome, and now he’s relying on ghostwriters and coauthors to churn out several books a year. His most famous series, the Alex Cross series, started out as well written crime stories, and now… they’re just unreadable. I finally stopped reading his stuff a few years ago when I couldn’t figure out if I had actually read a particular book before… That’s how formulaic his books have become…