Prisoner of Azkaban was the best. It's the best story and the best directed.
Sorceror's Stone second. For it's the classic.
And the Deathly Hallows 1 & 2 come in 3rd and 4th. For they were more exiting.
I know i'm probably in the (severe) minority here, but I thought Order of the Phoenix was the best. I've never read the books, and everyone who has says it's the worst book and Prisoner of Azkaban is the best. But I didn't like Azkaban even though I like the director, because I thought the subject matter sucked. Time-travel in movies almost always gets on my nerves.. (except Ninja Turtles 3 of course, haha). But the reason I liked Order of the Phoenix so much was because I thought it was pretty brilliant commentary on totalitarianism with Umbridge coming in. And then the finale with Voldemort was excellent.. kind of Star Wars-esque good side vs. the dark side within Harry.
That's a hard question. LoTR introduced many of the modern day epic themes found in culture today while Harry Potter focused more on themes like love and loyalty. On a whole, I think the LoTR had more higher quality adventure that I enjoyed but I also connected more personally with the boy who saves the world while going to school type of fun.
I started out heavily favoring Lotr over Harry Potter. The first Lotr was by far my favorite Lotr film. The series got worse but Harry Potter went in the opposite direction. As they grew more mature and dark the movies skyrocketed IMO.
Both are the best or top two fantasy franchises without another clear competitor IMO but Harry Potter in the end is better looking at the series as a whole. Now granted there are two more Hobbits but I just view them as the number 2 of the two.
I think that the Harry Potter and the Order of Phoenix is the best because it is a turning point. The war will begin, everything is gonna be more dificult. Loved the fight at the Ministry. The Order and the Death Eaters arrived like angels and demons and i got stunned.
However, it's is the saddest, because Siruis die.... I liked when Sirius came to take care of Harry, like a father to him...
But.. HP and the Order of Phoenix still is my favorite