I think that Michael Keaton's & Christian Bale's Batman are two wholly different characters. I haven't seen The Dark Knight, either, but I think I'll enjoy Bale's performance. For me, Keaton's interpretation is exciting & delightful. He always shows that certain spark & underlying sense of humor. I love everything he's done. Bale, on the other hand, can scare the bejeebers out of you. Another versatile & fine actor.