We weren’t arguing about the best one was more about religion vs agnosticism but you are 100% this is not the place to talk about that.
Not what we were talking about but yeah I agree. Back to the topic
I think the Witch Gods, especially Dreeg have the highest degree of Lovecraftian vibe
Dreeg is the one that pretty much makes you insane if you see him, right? If so, then I’d agree.
I love all of the references to primordial beings and other realities in Grim Dawn, and that feeling that there is more to the universe than meets the eye is definitely aligned with other Lovecraftian stuff.
Speaking of lovecraftian stuff - Charles Stross has a good thing going with his Laundry series, off which a nice taster is the short story Equoid: https://www.tor.com/2013/09/24/equoid/
Note - contains squick, lovecraftian take on unicorns, mild tentacle horror etc.
it would be so good if there was a class completely based on lovecraft
“the skill raises the insanity of all allies”
“summon a flying polyp”
“summon a caterpillar kraken crab pet” "
“shoot a beam of strange spacecolor with a weird smell”
I actually sometimes listen to music inspired by Lovecraft, during my playsessions of Grim Dawn. There is this Gothic metal band, called ‘The Vision Bleak’ that uses a lot of concepts from lovecrafts work. There is also their sideproject ‘Empyrium’ which is less Rock/modern music, but traditional instruments and singing. Quite haunting, dark and fitting to Grim Dawn.
There is also a dark ambient label, ‘Cryochamber’, which released several compilations on youtube, that are inspired by stories and myths about the eldritch, occult and dark. Maybe that helps someone to extent their playlist for gaming sessions in Grim Dawn 
Also great company while reading literature of the same genre/ in the same mood.
Ia ia Cthulhu Fhtagn 
It has also many tabletop RPGs. Best to played with good friends in a slightly darkened room.