Definetily the DS, it has such an huge amount of JRPG's, I think it's on it's way to surpass both the PS1 and PS2 in terms of sheer numbers.
If you want an mixture of WRPG's and JRPG's, then I would have to go with the PS3, not only for the RPG's that it has, but also because next year it's going to be a JRPG paradise for PS3 owners.
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"