Hehe. I also like the Virtual Boy, but my collection all Japanese plus the US exclusives. For the JP games only games, I really recommend Insmouth no Yakata. The game gets a lot of undeserved hate. It's extremely difficult, but one of the most intense FPSs I've ever played. It's so simple, but so frantic. An awesome game that all VB owners should have.
Space Squash and V-Tetris are great too. Space Invaders is old school style Space Invaders. Virtual Fishing is a fairly extensive game, but it bores me to death...
SD Gundam, Virtual Bowling, and Virtual Lab are the only 3 games I don't have. Mainly because they sell for about $600 each. Good luck!