During the course of obtaining 3 degrees, I had some super profs and others who really stunk.
There were, of course, a couple of foreign TAs whom we couldn't understand. Par for the course back then. Then there was one who was senile and gave us the same lecture several times.
There was a Soil Fertility professor who started the course with, "Any guys in here who are majoring in floriculture? Well, you're faggots." And an elderly Ag Economics professor who said, while lecturing to over 60 guys and me about cattle: "And now I'm going to use washing machines as an example so that Miss Carnation here can understand."
It's hard when you're a professor and you know of a colleague acting unprofessionally, as in AGDee's example. A few years ago at the college where I teach, there was a biology professor who kept coming to his 8 AM classes stinking drunk. He would slam into the board and fall asleep against it and the class would just sit there laughing and watch him...being freshmen, they didn't complain. When I found out from my students, it was hard getting the message across to the department chair, who really didn't want to hear it. Worse yet, he wanted me to teach the guy's courses when he finally dumped him mid-semester. Yeah, right, I really wanted to teach a 3-course overload for no extra money.