Blackmoore manor was pretty easy I think, I finished the whole thing in just a few days, but it can spook you towards the middle of the game if it is dark in your house, it gets pretty spooky but its a really cool game, Its one of my favorite Nancy Drew games. choose blackmoore manor, you'll be satisfied.
I think the hardest is blackmoor and the easiest is "Danger On Deception Island"
Easy Peasy
Personally, I think Message in a Haunted Mansion [MHM] is easier than The Curse of Blackmoor Manor [CUR] because it was made before it, so their are less puzzles to deal with, and it goes along much more quickly.
Haunted Mansion was created in 1983.
The haunted mansion is in the Eterna Forest
Message in a Haunted Mansion happened in 2000.
No
No.
Dangerous Dave in the Haunted Mansion was created in 1991.
Dangerous Dave in the Haunted Mansion happened in 1991.
Scooby-Doo's Haunted Mansion was created in 2003.
The Haunted Mansion - video game - happened in 2003.
The Haunted Mansion - film - was created on 2003-11-26.
Message in a Haunted Mansion was created on 2000-11-24.