1. Lucas di Grassi
Was brilliant once he turned up, nearly a third of the way through. He didn't throw away points like the two title rivals and would surely have won if he'd done the full year.
His season wasn't without its flaws, but he still showed that he has the ability for another shot at F1. Probably needed to win it more emphatically to get another shot, though.
This season was his coming out party as a complete racing driver, or at least it would have been if there weren't a few too many errors. Still, without just some of the bad luck he could easily have won the title.