RPG game huh. Imma chime in some of the best I ever play as well (which is some a few years ago).
The Pillar of Eternity (PoE) series is a good immersive RPG (not aware if this one got Co-op mode cuz I think i read somewhere it could?). The storyline is a long one like Final Fantasy classic and the side stories also interesting, like really interesting. I like to find those side story (or glimpse of "souls" memories on clickable NPC). The culture, religion is an element that interwoven in the plot that just..soooo goood. Although, I'm not really a fan for micromanaging type of game, for the sake of the story, I play.
Dragon Age series. I've play the first till end but havent complete the others. I think I got stuck on middle before I got busy but the game is memorable since it got some similarities in the setting like PoE. The graphics and stories hook me on (I'm a sucker for good story plot for game

). The game mechanics is simple enough for me to keep playing it too.
Ragnarok Online (RO) whether it be PC or mobile, it hold a special spot in my tiny heart

. The first ever RPG (or MMORPG) I play on PC with my brother. It was a fun community back then in 20xx(I didn't remember when I play that with my brother, but its a blast). I like chatting while playing in party and just plain goof around. No cheat, no mod, no hack, just plain grind and fun. The class system and boss mobs on town is like, whew. Its chaos but y'know you would still be having fun even if you died countless time (or when your healer bailed on you last minute lol) The graphic of 2D half in a bit pixelated pic is cute and very much on the in for that time. Haven't got in touch for the latest RO, but yea, it one of the best (How many times I said that already lol)