A few of the funniest ratings of college professors from RateMyProfessor.com:

#19: "His class was like milk, it was good for two weeks."

#16: "Three of my friends got A's in his class and my friends are dumb."

#12: "Instant amnesia walking into this class. I swear he breathes sleeping gas."

#10: "Not only is the book a better teacher, it also has a better personality."

#6:   "Very good course, because I only went to one class."

#5:   "He will destroy you like an academic ninja."

And the big winner, #1:

"She hates you already."