I'll have to go with Meteos also. I played the game to death when it first came out and was the first game I recommended to other DS owners.
Also the 2 SMT games, Devil Survivor and Strange Journey. I love those games as well and felt that they deserved to sell more. At least Devil Survivor got a re-release and sequel.
I could go on. I just love my DS. I sometimes wonder why I even have a Wii and 360. The DS gets all the love.
360 Games Now Playing: 360 Games unopened: Resonance of Fate Last 360 Game I Beat: Resident Evil 5
DS Games Now Playing: Dragon Quest VI DS Games unopened: Knights in the Nightmare, Etrian Odyssey III, Okamiden, Dragon Quest IX Last DS Game I beat: Radiant Historia
Wii Games Now Playing: Super Mario Galaxy 2, Arc Rise Fantasia Wii Games unopened Little King's Story, Sonic Colors, Silent Hill Shattered Memories Last Wii Game I beat: Sin & Punishment 2
