I recently saw both Ratatouille and Harry Potter and the Order of the Phoenix.
Ratatouille is the usual Pixar perfection: everything is very detailed and very lifelike -- the views of Paris will take your breath away and if you don't like rats, you will be creeped out. Despite this, it's probably last on my list of Pixar flix -- hey, somebody has to be at the bottom!
HP5 was good -- it's been some time since I read the story, so I can't speak to how closely the movie sticks to the book, but as a movie, it rocked.
I read somewhere that this might be the last HP movie they do because someone thinks the actors are getting too old to play teenagers. I don't agree; I had no trouble believing that Daniel, Emma, Rupert and the others were 15. I would very much like to see them film the last two books (but that could just be my completion fixation).