Cosmic Star Heroine might be the best new/original JRPG on Steam
Shadows of Adam is a great romp too
Xanadu Next gets a lot of love from people around here, but I can't say anything personally.
Other than that, you've got all the Final Fantasy ports. And the Trails in the Sky games, which I'm not a huge fan of, but a lot of people seem to be.
Cool thanks, I'll check those out.