PSP:
Persona 3 Portable - Shinji as a romance option should be enough.


DS:
Devil Survivor - Black Frost

Wii:
Phantasy Star (WiiWare) - Gonna assume it's the first one. Go play it. Don't look up maps.

PS3:
Batman Ahhkum Asylum - They did make a great Batman game. It's like TAS without the shackles.

PS2:
Shin Megami Tensei: Digital Devil Saga - That's a given. It's my favorite MegaTen game. And most likely my favorite game period.

SNES:
Final Fantasy Mystic Quest - Protip: Don't take the game seriously. Also it has Tristam, the loudest ninja ever.