I really liked Hidan and Kakazu. Especially Hidan because he could never die and I felt Hidan could have played a longer role than just in one arc.
Madara was good because I seriously thought he could not be defeated...till Kaguya came in.
I honestly wouldn't have minded Orochimaru. It was like he was all evil and then good. Same thing with Obito though I dont mind when it comes to Obito.