I normally find turn-based combat really boring but I find Shin Megami Tensei games so engrossing in part due to the combat. You need to pay attention to mechanics and properly prepare for each boss fight if you want to overcome them. It's not about just gathering enough exp. Do you know any games similar to SMT when it comes to gameplay?
Nocturne is my jam. I loved a review that called it something of a isolating, lonely and claustrophobic feeling of a game. And indeed when you are walking around the curved corridors of the kalpas, you feel like you are indeed deep deep below the earth.