I agree with @standbyme. As far as the actors go, there aren't "scarier houses" and "less scary houses." It really depends on who is working when.
What DOES change from house to house is things like gore, lighting, or the particular fear(s) that the house is attempting to play on.
Slaughterhouse is very gory but decently well-lit and is themed to cannibalistic butchers. There are parts of it where, with the right actors, you can have people approaching you on multiple sides--but again, that depends on how it's staffed.
Madame Fatale's Cavern of Terror is darker, which can make it harder to see what's a person and what's a prop, but it's not particularly gory. It's themed to a wax museum whose owner has a dark secret (the displays are made from real people!)
Cornered, at least in previous years, has been a dark, outdoor path lined with corn on both sides, and the actors are typically dressed to blend in very well with their surroundings. I believe the story behind it is that scarecrows are coming to life and want revenge. I would argue that the set pieces for this one don't really prime it to be super intense (there is zero blood--it's just corn), but again, it depends on who is working. It's moving to a new location within the park this year, and it's unclear what changes (if any) will be made to it with its move to Action Zone.
I'm not as familiar with C.H.A.O.S., but I don't recall it being particularly gory or dark.
KillMart is on the darker, gorier side (though not as dark as Madame Fatale's and not as gory as Slaughterhouse.) In that one, you are wandering a supermarket that has been overrun by zombies. In my experience, when KillMart is staffed by the right people, they can find very inconspicuous places to hide to get great scares... but that hasn't happened for me very often over the years.
Hotel St. Michelle is new this year, so your guess is a good as mine for what to expect!
I hope you and your friends have a fun time!