I'll ignore the ones that I've started but not finished as that would be way too long a list. Tales of Symphonia: I much prefered Tales of Graces skill system, and am hesitant to return to the MP based battles... Ni No Kuni: Bought it in a sale, but never had time to play it yet. Persona 4 Arena Ultimax: Have yet to finish Persona 4, so avoiding spoilers. Lightning Returns: Final Fantasy XII: Been procrastinating finishing FFXIII-2. (Not as much of a fan of the open-worldness of XIII-2 compared to XIII) Knights of The Old Republic 2: Keep forgetting it exists and playing SWTOR instead... LEGO Marvel Superheroes 2: Cause I play all the LEGO games co-op, and my sister hasn't wanted to play it yet. Detective Pikachu: Waiting for my sister to finish it first...
Octopath Traveler is probably the main one. I just really hate level grinding, but I love the game and even though I heard the final boss/bosses are complete bull I just want to finish everyone's character story.
Monster Hunter World is another one kind of. I want to play it through with friends but its a concrete fact that if I try and get people to try games I enjoy they will never play them.
Here are some games I started playing for a while, then stopped playing and never bothered to continue them. And it's not that I don't like them, it's just that I found some other (better?) games to play:
Digimon World DS: I'm currently VS the final boss but it kills me every time and I'm too lazy to level grind.
Detective Pikachu: I left it at episode 4, I still have to finish before watching the movie!
Pokémon Super Mystery Dungeon: Better than Gates to Infinity (which I beat) but still lacks some things that made PMD great.
You see... I started the game. Played a decent hour or two and really invested myself in it... But then I got stuck since I still haven't gotten a full grasp on the mechanics by that time... And haven't played it since.
One day I'll come back to it. One day... And I don't even know whether I should continue or start over.