I still think Darvish has had the best year. Cepsedes, Aoki, and Chen have had big impacts, and Iwakuma has been pretty good as well, but Darvish has had a big time year. His stats looks less than impressive, but he plays in a great hitter's park, and he's been a bit unlucky. His record is good, and his strikouts and walks balance out imo. Value wise, I think Chen and Aoki have been the best, but there is a reason Darvish is making as much as he is. I think he has a real chance at improving from this year to next, and then maintaining a high level of production, if he stays healthy, unlike many NPB imports. He just has really great stuff.