I couldn't really choose a favorite here because I like them all so much, so I put it as a tie. But oh man, so many to choose from: Harry, Voldemort, Newt, etc. And there's so many possibilities, such as flying around the map, and having magic battles with everyone. So cool.
The reason this is not number one is because we have had the chance to experience the magic in previous Lego games, so I thought a newcomer should take that spot.