Thr books are a lot better than the movies. They cut a fuckton out, significantly changed characters and entirely changed major plot elements for the films.
One of the biggest differences being Ginnie Weasely, who in the movies is a dull nobody with barely any lines, even less personality and a completely forced and unnatural romance with Harry that comes out of nowhere.
Book Ginnie is one of the best characters in the whole story and has an incredibly well written character arc, is core to multiple plot points and her relationship with Harry is incredibly well paced and naturally forming.
Also the books make Quidditch sound bloody amazing.
I'd also get the audio books, as Stephen Fry narrates them perfectly.