I only really liked 3 of the back 6, Honeymooners and the two-part finale.
I thought Role Models and the Tooth were decent but not great, and the Living Dead, while it had many nice moments, bummed me out big time with the Shaw-being-alive-thing.
That said, I enjoyed the finale so much, and believe that it will serve as the template for S4, that I'm feeling pretty good about the show's chances for ratings improvement this fall. I think Chuck S4 may hit its stride in a way that pleases not only the hard-core fans like us, but the more casual viewer as well. At least I hope so.
(moderators: Is there a back 6, worth the ride thread? If not I think we need one.)