...is the one involving Neville and the leg-locking curse. It helps set up Neville's character more, and it has Ron (I think) telling him that he needs to start standing up to people - which, of course, sets up his standing up to H/R/H and getting the house points for it in the end. As it is, I always thought the stuff of Neville trying to stop them came out of the blue, and if you didn't know the book, you wouldn't completely appreciate it.
I liked the fireplace scene, too, and the lads looked so cute in their Weasley Jumpers.
