First the Deathly Hallows... And then I would vote for Philosopher's stone. Coz thriller and story was best in the 7th part and 1st part gives a brief sketch of Harry's life and where he 1st knew he truly belonged... Its awesome... :)
Deathly Hallows because it was very exciting. I really liked the pacing in the book and film. Very nice ending to the series. Neville killing Nagini=BAD ASS!
I Amore the deathly Hallows because it ties up all the loose ends and answered most eh domande I had. But I loved the Prisoner of Azkaban because it was so different from the other libri because it did not focus mainly on Harry defeating Voldemort.