Well i'm of the opinion that most jRPGs today are garbage. Bad overly convoluted stories, boring formulaic characters and utterly uninspired combat systems.
There are ofc exceptions. Persona 4 is definitely one of them, as it excels in pretty much every area where the other crap fails. Story is interesting, great characters and a quick combat system. Tons of stuff to poke about with in between dungeons and all in all just a really good experience. Pretty much nails what jRPGs do well. That said, the Japanese school life setting might be off putting to some, so just be aware of that before getting the game (if you do, that is). Strongly recommended though.
I've been playing Bravely Default the last few days as well and i like it a lot. Back to basics. Simple yet enjoyable story, ok combat system that is also pretty fast and it's fun to try the different jobs. Well, at least the first 10 hours. I haven't finished it yet.
Other jRPGs that i personally think are great are the Suikoden games (mainly 1 and 2), Phantasy Star 4, Chrono Trigger/Cross and Final Fantasy XII. If you are in to strategy rpgs i would also suggest the Shining Force games and the original Final Fantasy Tactics. In general though, i think the genre is littered with really poor games, and a lot of games that get a lot praise even though they are quite mediocre (I'm looking at you, Final Fantasy). It's all about picking out the gems and leaving the other stuff...i guess the trick is to know what you like and what you don't like.
What was it you liked about Ni no kuni? What was it you disliked about the FF game you played, and which game was it?