One I forgot:
Surf Ninjas- Much like ET was the high point for Reese's Pieces, this is the high point for the Game Gear. May only be relatively unknown because my friends are trying to forget it, but I love it. Admittedly, that might just be because of nostalgia.
"What's this, I was playing Shinobi!"
---Nicolas Cowan (while you can clearly see the game is Columns)