Definitely the Lord of the Rings trilogy..! It's not even a contest!
Every scene is well done.. Peter Jackson and his team had an amazing eye for detail.. knowing when to show which perspective, coupled with the right music.
And of course many themes throughout the movies are simply of timeless value..
It has inspired an entire genre. Most movies are just temporary fun or quality. LotR is timeless quality.. Every new generation can find meaning in it..
Not to mention Tolkien's attention to worldbuilding, languages, species, etc. How many movies are based on such detailed work..? Few!