Mine would be: A true successor to Diablo 2 in terms of design/philosophy/mechanics.
As I have said in many of my guides:
Grim Dawn is what Diablo III should have been
It’s gloriously grim 
“The A-RPG that allows the best creativity.”
Very good game, very bad engine, lags me a lot, makes me wanna quit.
Grim Dawn -
“The three best ARPGs ever made, Diablo, Diablo 2, Grim Dawn. Everything else is forgettable.”
You can wear soiled trousers and throw your fecal matter to enemies.
‘I’ve lost count of the number of times I’ve been one-shotted.’
The spiritual successor to Titan Quest, and it has guns and Cthulhu in it.
Better than Diablo 3 and Path of Exile.
A quiet, solid and slow ARPG set in a gloomy world and balanced around a good single player experience with many viable builds and choices.
"If you submit feedback or ideas about class balance, The DEV’s will say you’re bad "
It’s smashing!
A hack and slash RPG that actually encourages hacking and slashing instead of playing capitalism simulator on a third party site.
“If Titan Quest and PoE had a child, it would be called Grim Dawn.”
Quoted for the pure and sincere truth!