Definitely Prizoner of Azkaban. While the first two are very faithful to the books, they are overstuffed and thus give no time for the characters to breathe. Goblet of Fire does let its characters develop, but the plot is rather lackluster. PoA is by far the most focused, leaning in on the elements that it needs to, and developing its characters in a way that compliments the film as a whole.

The ones that grow more darker.

The first one because I didn’t know about Harry Potter until I saw the Sorcerer’s Stone. It was the first step into a magical adventure.

Out of these, Chamber of Secrets- however my all time favorite has to be HPB.

PS is my personal favorite. Its jut th perfect entrance to the wizarding world

The ones that grow more darker.

MWHAHAHAHAAAAAAAAAA! ANOTHER EEEEEEEVIL HOOMAN! IM SO HAPPEH lol

Hey, I've edited this post to Opinions- please be mindful of the categories :)

I agree with @TheCritic&RobloxMaster21 that darker the better

Prisoner of Azkaban

Goblet of Fire

Chamber of Secrets

Philosopher's Stone