64 DS
Don't tell Popo.*
The lesser-known "I missed" trophy
"Oh no! It's our arch nemesis! Fire-Man!"
Also, Fiery Men
Luigi has no mansion.
Lucas realizes that Mewtwo, Articuno, Ho-Oh, Groudon, and Uxie all left him AND stole all four of his Master Balls, and panics.
*As far as I know, the Ice Climbers' relationship isn't official--they could be brother and sister, aunt and nephew, whatever. I read Sakurai pictures them as lovers, though, and so do I.