Considering HGSS are fundamentally different games than the original Gold and Silver, I think it's a bit unfair that they cannot get a vote here :(
Oh well... I will say Wii Fit Plus. Terrific game, no joke. I remember playing it with my family... and it was A BLAST. Even better than Wii Sports/Resort. So many games and exercices...
Also, during the pandemic it helped me loose 25kg! I went from 90kg to 65. All thanks to Wii Fit Plus and eating less. Forever grateful to this little game and the Balance Board ^^