I really want to play a Final Fantasy game at some point, but always seem to find something else play. Same thing goes for Dragon Quest games. I could ask everyone here which game from each series you recommend, but would I actually play it? Probably not. 😔
As for a single game I own, I will probably never play Disgaea 5. It's been so long since I bought it.
Core functionality of the game is actually a log and it's very easy to revisit things to help your memory. But i found it so compelling, i rushed through it in two settings. It's a truly unique and wonderful game and i can't recommend it enough.