Darkest Dungeon (Hardcore at its best)

Darkest dungeon is an insanely hardcore permadeath RPG.

If you haven't played, the gist of the story is gathering a team to recover/destroy bosses in ruins from an old family estate by hiring mercenaries.

Its Permadeath and you WILL lose items and Characters. Its insane how hard the game is especially with the crimson curse DLC.

You'd think then no one would play it... Rather... It is addictive.
You have to gamble with characters you really love, have invested in, and risk death. Balancing strategic retreats as to preserve or to take a risk to finish the dungeon is exhilarating. The game gets your blood pumping as you take on a  boss with your best team hanging on by a thread as you manage stress, health, personality quirks, and disease.

This combination of stat management, character building, and rouge lite elements in dungeons create for a real heart pounding experience. When you do defeat a boss with your whole team in tact (typically stressed and going insane but... alive) you feel intense adrenaline and the reward loop is amazing. It's not grindy feeling as your team is constantly switching up (characters can't always handle taking dungeons multiple times in a row), and it really makes you sit and think.

There is also management of your party outside fights, from light level to food supply.

It really keeps you on your toes and I think its hardcore done in a perfect way (especially when i lose a character i cherished phew, its emotional)