Remember, even Gunstar Heroes didn't sell all that well. It's not obscure anymore, but it was back in the day, I suppose. Light Crusader definitely counts. I actually played through the entirety of Treasure's Genesis catalog for some articles not too long ago. McDonald's Treasure Land is pretty obscure, but it's not as good as its spiritual successor, Dynamite Headdy (seriously, I think they may be using the same engine), and by the same token, Yu Yu Hakusho is interesting as basically a proto-Guardian Heroes.