Evanna Lynch was the perfect Luna Lovegood. Maggie Smith was the perfect Professor McGonagall. Alan Rickman was the perfect Severus Snape. Imelda Staunton was the perfect Dolores Umbridge. Helena Bonham Carter was the perfect Bellatrix Lestrage.
Now, I’m sure not everyone agrees with the above, but I get the feeling that this is the general consensus. I’m not exactly going to disagree. I suppose it depends on the definition of “perfect”. In my humble opinion, every single one of these actors did an amazing job, but they did actually portray their characters quite differently from the books.
Another example of an actor who gave a great performance but did not portray the character from the books is Emma Watson as Hermione Granger, and I’ve discussed that at length here. So I’m just going to focus on the others here. My analysis is based purely on my own perceptions of whether the movie characters fit the roles when I reread the books.
Luna Lovegood: Movie-Luna was delightfully quirky as opposed to borderline insane, as book-Luna seemed to me. Put differently, in the movie, Luna’s eccentricity was toned down a lot. But actually, Evanna was everything I had wished book-Luna had been. And what is worse is that she had splendid chemistry with Dan, which to me, was like adding salt to injury for a disappointed Harry/Luna shipper like myself.
Minerva McGonagall: Movie-McGonagall was much nicer compared to book-McGonagall. She wasn’t as sharp-tongued or as intimidating. The book-McGonagall is the kind of teacher I’d be scared to be around, and the movie-McGonagall is the kind of teacher I would make friends with. As an illustration, imagine the scene in the book where Umbridge inspects McGonagall. I can’t picture Dame Maggie Smith’s portrayal in that scene. Or imagine the scene in the movie where Umbridge accuses McGonagall of disloyalty. I can’t picture book -McGonagall being as publicly overpowered (the Umbridge going up the stairs and McGonagall going down the stairs was meant to portray Umbridge establishing her dominance). Also, I can’t picture book-McGonagall teaching her students how to waltz. The funny thing is, Maggie Smith has seemed more intimidating as Countess Grantham in Downton Abbey. (As an aside, when reading the books, sometimes I subconsciously pictured someone like Meryl Streep’s Miranda Priestly from The Devil Wears Prada.)
Severus Snape: Book-Snape is a lot more unpleasant and belligerent than Alan Rickman could ever be. When I tried to read OotP again, Snape’s dialogue just did not seem to fit with that slow drawl we’ve all come to associate with Snape. (I’m thinking of the scene where Snape visits 12 Grimmauld Place and gets into an argument with Sirius.) But Alan Rickman’s performance was fantastic, even if I can’t ever picture him as Snivellus! RIP Alan Rickman.
Trivia: J. K. Rowling told Alan Rickman from the very start the truth about Snape. Pretty much no one else knew about it.
Dolores Umbridge: Of course in the movie she looked different. Imelda Staunton looks nothing like a bullfrog. But she did nail the girlishness hiding the inner sadist and the desire to have order. She replaced the throat clearing (hem hem) with a giggle, but that worked pretty well.
Bellatrix Lestrange: Helena Bonham Carter did such a splendid job with Bellatrix that she is actually one of the first of the cast to be billed, even though Bellatrix isn’t in the first line-up of characters in the book. Movie-Bellatrix is actually way more over the top and much more insane than book-Bellatrix, but that’s what makes me her performance so much fun. Book-Bellatrix was a lot more serious. I doubt she would have maniacally screamed “I killed Sirius Black” or dance around on the tables on the Great Hall wreaking havoc, but book-Bellatrix, intimidating as she was, never made me regard her as one of the best characters of the series. That was all Helena Bonham Carter.
Apart from these amazing performances, I can think of a few more who reinvented the characters.
Jim Broadbent as Horace Slughorn is one. Of course he missed the trademark walrus mustache, and he played the character a little more comically than in the book, but his performance was great!
Gary Oldman as Sirius Black is another. My teenage-self, who had been very taken with how hot Sirius was supposed to be was very upset at the casting. But appearances aside, while Gary Oldman did a great job portraying his relationship with Harry, he wasn’t reckless, hot-headed or mischievous the way Sirius is supposed to be. I just can’t see him as the bully Sirius was when he was young; I see a level-headed young man.
Then there’s David Thewlis as Remus Lupin. He seemed a little too impatient for the character; and wasn’t as calm and collected as book-Lupin was.
And how can I not bring up Richard Harris and Sir Michael Gambon as Albus Dumbledore? There are people in both camps of who did a better job. There are some who swear Richard Harris was perfect, and some who think he was too old and frail to play Dumbledore. While I think he captured Dumbledore’s friendly attitude and exuded the right sense of grandness, I also don’t know if he would have been able to pull off the action scenes in OotP and HBP. On the other hand, while Michael Gambon looked right for the part, with his casting, Dumbledore went from a calm collected regal perpetually smiling person to an irritable angry and impatient old man. He did do a much better job starting from HBP; maybe he finally read the books or watched the first two movies! But come on now, we all know that Ian McKellen would have been the perfect Dumbledore, but you know, being Gandalf AND Magneto was probably too much of a responsibility already.