Can we please just talk about how sassy Professor McGonagall was?
Just look: "Ah, of course. There is no need to tell me any more, Ms. Granger. Which one of you will be dying this year?"
I mean really: "I should have made my meaning plainer," said Professor McGonagall, turning at last to look at Umbridge directly in the eyes. "He has achieved high marks in all Defense Against the Dark Arts tests set by a competent teacher."
So much sass: "Are you quite sure you wouldn't like a cough drop, Dolores?"
She's just full of it: "I doubt it will make much of a difference," said Professor McGonagall coldly, "unless a mad axe-man is waiting outside the doors to slaughter the first into the entrance hall."
Her zingers are the best: "Well, usually when a person shakes their head," said McGonagall coldly, "they mean 'no.' So unless Miss Edgecombe is using a form of sign language as yet unknown to humans --"
Seriously though: "You look in excellent health to me, Potter, so you will excuse me if I don't let you off homework today. I assure you that if you do die, you need not hand it in."
And finally, my all-time favorite: "It unscrews the other way."
