Who is your favourite director?
Pretty related to the previous question. I loved Chris Columbus and his approach because the magic was literally oozing out of the movies and it all felt really Harry-Potter-ish. He managed to capture the magic, the mystery and the Harry Potter feeling everyone fell in love with in the books already. I would also daresay he is the director people will remember best if asked about the Harry Potter movies - even though he only directed only the first two!
And moving on to my choice for worst: I think Alfonso Cuaron completely screwed up the third film. As one film itself it wasn't that bad; however, you simply cannot change everything in one film from the landscape to the uniforms and suddenly let them run around like overly cool people, it's no match. Honestly, I'm not sure whether that's on him, but I really disliked that about the movie. You cannot make such changes amidst a series of movies...