Which Investigators expansions would you say are the best to get?

Hello everyone,

My collection of the game so far:

• Revised core set
• Hemlock Vale campaign
• Hemlock Vale Investigators' box

Yes, I am fairly new to the game. I have played the Night of the Zealot a couple of times and completely got hooked. Then I decided to get the full package for Hemlock Vale since I really liked the setting for the campaign and I am currently a few scenarios in my first run with friends (party of 4).

I have searched online for videos or articles about investigators' expansions but have had no luck. Most of the things I looked up talk about singular investigator or card but not really the box they come with. And since I would like to get another investigator's box I would like to hear your thoughts on them.

Which one do you consider the best?
Which one is the most well-rounded?