Lost Odyssey for me is the best game on the 360 with a great story which everyone who loves jrpgs should play this.one of the best for me,so underrated.if you had to play one game,its gotta be this
Shin megami tensi,lucifers call/nocturne the best jrpg on the ps2 for me ,dark story great battle system id kill for a remaster of this game ,looked great on the ps2.
Enchanted arms on the 360 ,i absolutly loved this game,it uses a grid based battle system with monsters you buy and gain during the story,another underated game.
Persona 4 golden,i spent weeks on this game and i couldnt stop playing untill i finished i was taking my vita to work and playing any second i could.perfect game same goes with 5(ps4)to be honest near perfect game.
Jade cocoon 1+2, ps1&ps2
Two very different jrpgs but i loved them both,like pokemon you use monsters to battle it out,the second goes a bit more childish and no as serious as the first but uses a brilliant battle system with 3 monsters at a time,you can take up to 8 monsters and switch to one of 4 sides each with thier own perks and disadvantages.not many enjoyed the second but i put over 100 hours into it multiple times.
I think this was the first game in the shadow hearts series but i may be wrong,for me the best game on the ps1,feels a bit dated now but it was an amazing game and you should try this.
Shadow hearts ps2
The first game with a battle system that took skill to master,every attack you have this battle ring with two or three yellow markers that you have to hit perfectly as the arrow revolves.brilliant story and brilliant characters in a beautiful gothic world.
Final fantasy x ps2,ps3,ps4,probably ps5.For me the best game in the series(yeah i said it ) i loved it from start to finish ,the battle system for me was perfect,the leveling up system was perfect with the sphere grid and the customisable weapons were great for the end game,which for me the end game was just the start of the game for me as i spend so much time completing all the side quest to get the best weapons and the secret aeons ,defeating the dark aeons,collecting ten of every monster for the battle arena,finding all the celestrial weapons i had some much to do at the end it was just so enjoyable and i would recomend you actually try this game instead of listening to what people say about it.
Also blitzball was fun for me