My experience has been that the quality and friendliness of professors varies greatly. But there is always one that stands out. Yesterday in class, I actually raised my hand to volunteer an observation on a case in one of my classes [those of you that know me well, this should not surprise you]. This is a class that I would not normally enter the fray in, just because I know nothing about this area of law. Anyway, the Professor looked at his seating chart first and called me by the wrong name. To which I said, "Do you mean Lisa?" And he apologized and said yes and I gave my comment.
To my surprise, about 20 minutes after I left class, I received an email from the professor where he apologized again for the mix up and then said, "Really great comment in class today. Exactly what I was looking for." This type of encouragement and praise is rare. When a professor goes out of the way to encourage, it is something I value.