I have no clue why people say Luigi's Mansion is the best of the trilogy. It isn't. I will now show you the Pros and Cons of all three games.



Luigi's Mansion
Pros
-Has unique bosses
-Good sound effects
-Good final boss

Cons
-Bad ghost designs
-Bad cutscenes
-Plot isn't too good
-Lower in quality

Luigi's Mansion: Dark Moon [And 2 HD]
Pros
-Good plot
-Higher quality
-Good ghost designs
-Good final boss
-Scarescraper multiplayer is pretty cool

Cons
-Bosses were less unique
-Problem solving is sometimes unclear
-Repeating cat-and-mouse chase with Polterpup

Luigi's Mansion 3
Pros
-Great graphics
-Amazing sound effects
-Amazing boo designs
-Loyalty to the plot
-Polterpup is an ally

Cons
-Plot already used
-Ghosts are copied from Dark Moon
-Final boss isn't good
-Other bosses are basic
-The Polterpup thing was replaced by the hotel keeper's cat



So after doing my research It seems to me that Luigi's Mansion: Dark Moon [And 2 HD] was the best of the triology. You may have your opinions, and if you do poease comment them below. But me personally, I think Dark Moon is the best.