Dumbledores actor changed twice because the one that was in the 1st. and 2nd. movie died. The actor they have now is great though
As for Harry, Ron and Hermione it's perfect!
Alan Rickman is the greatest Snape ever.
Helena Bonham Carter is amazing as Bellatrix of course <3
I didn't think much of Lupin's actor. I mean, he had to look like a werewolf a bit in real life, we they grew the guy a beard
Did anyone know Johnny Depp might play the older Harry? Yaay!!