As much as I love it, probably Pokemon.

would be impossible to give another shot as I long gave it away to a friend

Maybe Dragon Quest 1 since it barely has a plot. Most jrpg plots are kind of stupid so it's hard to pick, and this is coming from a big fan of the genre. Tales of the Abyss was pretty awful. I thought Grandia's story was bad, Lunar Genesis literally bored me to sleep, Omega Quintet is the most stupid shit I've ever played but what do I expect from a jrpg/idol game?

I actually like all those games listed above, it's just that the plots, like most jrpgs are pretty bad.

Oh boy.

Dawn of the New World.

By itself is a really generic, unsatisfying story, with very badly paced character development, for some not at all, really lack of anything worth nothing RPG story.

But...

Is also a spin off/sequel to not only a Tales of game, but one to Symphonia, a title with a rich world, story and character development.

My biggest problem with this game truly, is that is a pretty bad Tales of story, is not a game worthy of that name, character interactions are there, but most are uninteresting, the Symphonia 1 cast gets zero extra development and they completely went against some of Lloyd's ideals that made him the character he was in the first game.

Added non sensical elements like the centurions and Ratatosk to the world of Phantasia/Symphonia, they don't add anything that wasn't there already, just an excuse to go on an adventure and in cases, contradictory.

And the new characters don't help, Emile is a poorly done Luke and Marta gets 0 development, annoying to no end protagonists and Richter was also nothing noteworthy. Complete waste of time.

A game that just trashes the legacy of one of my favorite RPGs. Badly done fanfiction the game.

I don't expect Game Freak to expand upon the politics of its world but I would really like to see how the school system works. Why do some kids go school and others don't? Is there schools that don't focus on Pokemon? What's the age to stop attending? etc etc...

i didn't play FF XV, but the trailer of 4 dudes riding in a sportscar is pretty laughable and I just can't imagine that it was very good. It gets my vote unless someone can defend that atrocious concept.

I assume 10, as that's when you can get a Pokemon and leave home 

Pokemon for sure xD but I've played so many jrpgs I need to think long and hard if there are worse.

Once upon a time I would have said something like Star Ocean Till the End of Time, I have since changed my stance on that one. It's 4D beings concept is actually one coming from a higher understanding in Life Creates Life theory and our small position in the grand scope.

Probably any of the Hyper Neptunia Games. Or I Am Setsuna....hated that game from the start when I was introduced to "Sacrifice Town"....cringe. Magna Carta was a game that I remember really frustrating me, but that was less about it's plot and more about it's poor handling of characters and combat. I have a lot of issues with Final Fantasy XIII but I am not willing to completely dismiss it because it's background lore is actually really strong. It's sequels are utter garbage tho, retconing many of the original game's themes. The Tales of Series plots are notoriously 1 Dimensional and Anime tropey for me. Wouldn't entirely write these off either......Draganeer's Aria? A game for PSP, definitely was predictable and terribly paced from what I can remember. I despise Digimon Cyber Sleuth's story not because it is necessarily bad but because it overbearingly impedes my Digimon collecting. Same thing for Pokemon.....no one cares about their story I am just trying to collect!

I feel like I am a pretty good judge of character on games so I rarely get blindsighted by truly horrible games. I probably have more games that I was actually gleefully surprised how their conclusions turned out. Like White Knight Chronicles 2, started out extremely predictable but turned into something marvelous.

Gonna echo Twi with Tales of Symphonia: Dawn of the New World. Not only was it a horrible follow-up to my favorite JRPG, but the story itself was stupid even in a vacuum. Extremely contrived motivations, no one acting in-character (except maybe Zelos), and some plot devices so bad I swear I was watching a daytime soap opera. Who in the hell thought Evil Lloyd was a good idea?

Close second would be Bravely Default. While the setup is kinda nice, albeit simple, the direction it goes after chapter 4 makes the characters feel so mind-numbingly freaking stupid I question why I kept up with it. Even separating the moronic characters from the overall plot, the entire setup felt like a poor excuse to just recycle content forever, and it just became hard to care about anything after doing the same thing over and over again.

If you asked me a year ago, I would have said Fire Emblem: Fates, but after playing through all the routes and the story-relevant DLC, my opinion has since been updated from "Stupid story" to "Interesting story told in a really stupid way." Honestly the lyrics to "Lost in Thoughts All Alone", the translated texts, and the DLC probably tell the story better than the actual story did. Obviously not a good thing by any means, but I can at least appreciate what the writers were going for...at least at some point in time, as it does feel like the story went through rewrites without properly connecting everything.