On christmas Molly gave this furry, ugly sleeveless jacket to Ron and after that Hermione said sth like :
- I don't understand,why don't you wear it, Ron?
- Blimey Hermione!I look like an idiot!

Shacklebolt's reaction on Dumbledore's disappearing: Admit it, he's got styyyle!- this one sparked lots of laughs in the audience!

This is all i can think of at the moment