The reason why I didn't add more is that these are the ones who had more than 3 lines of part.
But of course, everyone should feel free to add whoever s/he likes, just remain in grown up category. (Michael and Oliver Phelps counts to Youth)

They were all good !!! These HP movies are like the Who's Who of acting in the UK and Ireland. I've never seen so many good actors and actresses in such a long series of films. There is not a single mishap in casting throughout the movies.

In my opinion, these movies can make good teaching material for youngsters that learn English - I would advise anyone learning English to watch these movies in their original version. Good diction, no swear words, enthralling story, good acting and filming. I'm 40, yet I'm a fan !

But I had to add Alan Rickman (my favorite by far) - Ralph Fiennes, Bill Nighy, Helena Bonham-Carter and Rhys Ifans had also more than 3 lines. Alan is awesome as Severus, as if he was born for the part.

Alan Rickman acting is pure greatness

That's exactly why I added them here. Julie Walters however did not have 3 lines this time.. So she ain't on the list.

As usual.

They were all very good though.

Helena is AMAZING!

I think these 3 were amazing!! (Especially the guy who was Harry) - I thought his 'walk' after seeing Umbridge was absolutely hilarious.

Alan is always perfection :) But I loved how Jason played Lucius, not the confident, arrogant bastard anymore, but a broken, frightened man. He was great!

Helena is the BEST!!!She really is the perfect BEllatrix!!!Also alan and jason are amazing actors!!!Also Ralph Fiennes as Voldemort is awesome!!!And the ministry three were really great and Nick moran as scabior!!!Well actually all of them here except bill nighy who i really didn't like as rufus scrimgeour!!!

i think the "bad" guys are giving the best performances in the movies. Helena Bohnam Carter, Alan Rickman and Ralph Fiennes are excellent for their roles. They are exactly as I imagined them.

Definatly, Helenba alaways does amazeing

These three were awesome. It was really strange thought to see three people who are better actors pretending to be the trio :)

I really liked him, also Helena :D

She is wonderful and amazing and a goddess and I love her so very much!

Jason Isaacs and Nick Moran get very honorable mentions for being so dead sexy and creepy at the same time.