The titan fights sucked. Hard. There should be more to bosses than just looking cool; for example, the huge bosses in Bayonetta are not only highly mobile but actually pose a threat. And I've said it innumerable times before, but fuck shimmying across ledges. I don't know who said that counted as platforming, but they need to be shot.
Most of the other bosses were just regular enemy patterns with a huge health bar and some ways to restore their health, but I particularly enjoyed the mecha-scorpion fight and evil butcher fight, because of their appropriate horror fucked-up-ness.