In my case, apart from the already mentioned Tengai Makyou II (which I think it has at least a remote probability of being translated sometime in the future) there are two jrpgs that had caught my attention for a long time but highly doubt any of them are going to be translated ever.
One is "Miraculum, the Last Revelation" for the pc-fx. A pretty nice-looking 2D pixel-based rpg that looks and plays a lot like the snes Final Fantasy entries, particularly V and VI, but it also has FMV and voiceovers.
And the other one, the pc-engine version of Gulliver Boy (nothing in common with the mediocre snes action rpg based off the same TV show) Looks like a solid rpg and was published by Hudson, which used to release pretty good rpgs back then.