This is why I chose PoE and Grim Dawn over it any day. Diablo 3 was a cartoon masquerading as a Diablo game.
Personally, I thought D3 was WoW masquerading as Diablo. I'm also quite surprised Bliz even had a demo of D3 because from what I played of the D3 demo, nothing from the previous 2 games were preserved, fans of the previous game weren't likely to like it.
For atmosphere, D1 totally nailed it. The music, the gritty art design, monster design and the fact you could still die on the second level if you weren't careful. Just my opinion but I think the atmosphere alone was what made the demand for D2. I know people will disagree with me but I thought D2 lost some atmosphere that made D1 special, I actually didn't like D2 when it first came out. Eventually after a ton of patching, D2 won me over and while I still don't like the loss of atmosphere, I think the character progression system makes up for it. D3 reatains none of these things. If Bliz called the game "Fisher Price My First ARPG" instead of Diablo 3, I would have been more forgiving over it.
I also like Grim Dawn, and I can't wait for the Forgotten Gods expansion due this year (November I think it was)
I should probably expand on why I said that: I kinda feel like WoW IS cartoony, which is why I've never been a fan of it, nor even played it. I played the shit out of Warcraft 1 & 2, but they somehow lost me around Warcraft 3. No judgements on that game, as I've never played it.
I would actually have to say that D1 is probably my favorite Diablo game as well, even for some of its linearity, they absolutely nailed the gloom, the atmosphere, the aesthetics and the designs. I mean, who can forget their first time stumbling into the Butcher's lair and hearing him growl "Ah, fresh meat" at you?
Diablo 2 is one of those games I loved when it came out, and am finding that I don't like as much as I did back then. Somehow they got a little too stuck up their own asses when it came to some of the dungeon designs, drawing them out until they're more grind than entertaining, whereas a game like Grim Dawn or Path of Exile has this atmosphere in every dungeon that makes you want to continue to explore, with lots of interesting scenery, or horrific nightmarish scenery, as the case may be. (Especially in the later acts of Path. Holy shit.) D2's skill trees and character progression also have not held up over the years, when in competition with those two games, and D3's is a laughable offense.
But yeah, I do like Grim Dawn's grit and desperado style areas, mixed with magic, steampunk and a pretty cool style. I plan on picking it back up once PoE's new Incursion season is over. :)