This question is insanely hard
! I would love to have long debates with several different Professors, given that they are extraordinary wizards (and often have quirky personalities!). If I were to ask any of them a question, it would only lead to the next, and the next, and the next... The impossibility of asking more than one would leave me entirely unsatisfied, and probably more confused than I was before. Taking this into consideration, I believe I would pick Professor Rubeus Hagrid and simply ask him for a half-giant hug (that's better than a bear-hug, right?)
Which is your favorite charm?