It's actually rather difficult to watch the earlier Harry Potter movies now, because the characters have come such a long way by 2011's Deathly Hallows Part 2 that it's a challenge to take them much seriously when they're squeaky-voiced and tiny. Still, 2001's Philosopher's Stone is an enjoyable children's adventure, one that's followed up by an equally entertaining Chamber of Secrets, before Alfonso Cuaron helped transition the series towards a darker tone with the Prisoner of Azkaban. As the children get older and story becomes increasingly more downcast, the Potter series becomes a whole lot more involving, leading to the epic finale that is easily the series' best entry. Though not every plot in every Potter movie was better than what came before, the feeling of progression towards that end-game was more palpable in each film, and of course, Radcliffe, Grint and Watson simply became much stronger actors as the years passed.