Games to grind for hours

Hi, I'm currently looking for grindy games. I just want a game I can kinda shut my brain off and grind for items/Gear. Any genre is welcome, however, I would like something that does not require me to spend additional money (so no P2W) as I'm a student. Also I would like something that does not require me to play with a team. Thank you in advance! (I'm on PC btw)