They're comparing trilogies bro?
LOTR lost my vote when Sam and Frodo went all Ace and Gary in the third and Peter Jackson decided he couldn't cut any of the 12 false endings.
Godfather trilogy is great until the last movie. Then it's only one great film, one good film, and poop.
Star Wars is probably more complete, more consistent. But let's be honest. It's not a trilogy.
Batman is good, but the writing in the last one was iffy and the first one is like Unbreakable, it's awesome but not everyone gets it.
The most complete trilogy of all time is most definitely the Sleepaway Camp trilogy from the late 1980s.