Well, I haven't seen that many episodes from this season, but of the ones I have seen, the FaiChii had the best animation although the overall plot was a bit too sweet for me and I'm starting to think that I'm alone in the world of not liking Dreamscape - however, Chii's little speech at the end was quite cute, I must admit.
As for Kuro's Past, it was nowhere as near moving as in the manga (big surprise, no?) and our brave little ninja didn't look small and cuddly enough to me. Still, episode 40 could count as my favourite one, since young Kuro's seiyuu was such a pleasure to hear. That's good acting for ya.