Omg Legend Of Dragoon :( :( it has to be like the most forgotten, underrated and overlooked JRPG of all time, it deserved more attention, that game is just epic and big, I mean, it was one of the very few PS1 games that had some voice acting, not much but it was something big at the time xdd. It deserves at least a remake! xd :D
I also played shadow hearts: covenant and it was awesome, that game is long and the story is quite interesting, is also and JRPG that deserves more attention. I also played shadow hearts: from the new world, but in my opinion it was not as good as its predecessor.
I believe that the Wild Arms series is a very well known saga in the JRPG community I think xd. So in my opinion, Its not that forgotten xdd. But is quite overlooked these days xd.
The others I do not know because I have never play them.
I think that other JRPGs that are quite overlooked and deserve more love are Grandia III (is neat, I liked it), Legend of Legaia (the first one, it was epic), Rogue Galaxy (awesome game), Valkyrie Profile 2: Silmeria (even though is like a 2d game, is really good), and the Xenosaga series, which I liked, but I think that a lot of people hated xd.