They are.
I enjoyed Oblivion thoroughly, even though like Morrowind it was insanely easy to game the system into being all-powerful, like with my most-played character whom I have nicknamed Mr 100% Chameleon. It's not that catchy a name, I know. Anyway, I completed all quests with him. All of them. Erry day I'm backstabbin'. I'm actually hoping that Skyrim will have that too, because as soon as I run out of legitimate things to do to keep me entertained, powergaming can offer hours upon hours of more fun.