I am of the opinion that Hell House LLC III is better than Hell House LLC II. In some ways I think it's actually better than the first two because the characters seem more like real people, somehow, than even the first one which is considered the best of the franchise. In Part 1 Sara is probably the most relatable character while Paul is the least (I think this is intentional because they want you to suspect Paul is just toxic and messing with everyone, possibly having a nervous breakdown). But in Part 3, Vanessa is a completely well-rounded female character and Harvey - while somewhat stereotypical - is less hollow and basic than the straight frat boys lined up in Part 1. Even Russell is very convincing as the narcissistic, crazy rich man, the actor has that tell-tale overly thin cyclist physique that many middle aged wealthy men have.
Tl;dr - the character development in Part 3 is the best of all three films.
HOWEVER, the ending is cheesy af and is nowhere near as eerie and scary as Part 1. So overall I'd say watch Part 1, skip Part 2 and just follow-up with Part 3 in the Hell House LLC franchise.
Tl;dr - the character development in Part 3 is the best of all three films.
HOWEVER, the ending is cheesy af and is nowhere near as eerie and scary as Part 1. So overall I'd say watch Part 1, skip Part 2 and just follow-up with Part 3 in the Hell House LLC franchise.