So far this season, "School Reunion" (very nearly a perfect episode, as I said in my reply to xparrot above) and the Mickey arc have been the real standouts for me. Just very, very well-done television. (And I must confess that I didn't specifically recognize Sarah Jane -- I mean, I knew she was an old Companion from one of the seasons, but I wasn't sure which one! I've seen a fair amount of the old series, but rather randomly, because I used to watch episodes on TV in a haphazard kind of way. I recognize Daleks and Cybermen and K9 and so forth, but don't ask me where or when any of them were introduced.)