Animal Crossing for DS.
It would have been Elite Beat Agents...but I recently lost it.
I lost Mario Kart, and now EBA?? My 2 favorite games for the DS by far...which only makes it harder because I feel the need to rebuy them.
LEFT4DEAD411.COM
Bet with disolitude: Left4Dead will have a higher Metacritic rating than Project Origin, 3 months after the second game's release. (hasn't been 3 months but it looks like I won :-p )