My personal favourite at Apple is currently Craig Federighi (in terms of performing). When he first demoed Lion back then he was pretty nervous but I think now he's grown up the the role and I really love his presentations. He looks humble, yet entertaining, makes you really believe that what you're seeing is awesome. And I can imagine that a lot of nice features in iOS 7 come from him (or his team), because with OS X they are doing an excellent job.
In comparison, I never really enjoyed Forstall's presentations nor his ideas.