A very nice site for reading up on SNES JRPGs:
http://fantasyanime.com/games
Lots of info and screenshots there.
My own personal favorite JRPG for the NES would be
Front Mission: Gun Hazard. Granted it's an action-RPG (but you do get experience points and level up). Yet there's enough customization to yourself and your sidekicks, as well as an intricate plot, to warrant the RPG aspect IMO. Either way it's an amazing experience not to be missed. I would also personally consider
Demon's Crest to be an action-RPG, and I love it too.
As far as traditional turn based SNES JRPGs go, it's hard to beat
Final Fantasy VI.