Tough.
1. Deathly Hallows Pt. 2: Only thing I hated was the ending, but tbf it was in the book.
2. Goblet Of Fire: I love movies that center around competitions, and Hermione.
3. Chamber Of Secrets: Tom Morvolo Riddle & Lucius Malfoy. Great acting too.
4. Sorcerer's Stone: Nostalgic, but I don't think the acting was all that good. 50/50.
5. Prisoner Of Azkaban: Angsty Potter overreactions killed this for me.
6. Deathly Hallows Pt. 1: For starting the "let's take our last movie and divide it into 2 parts" bullshit, mostly.
7. Order Of The Phoenix: Dull, and it says a lot that some minor villain like Umbridge outshines Voldefuckingmort.
8. Half-Blood Prince: Beyond fucking dull for me. Fell asleep first time watching it.