I think it still would've done well. I got mine for Super Mario Land. Primitive as it was even compared to later GB games, it was still MORE MARIO! and that was a way to move systems. I'm really glad it wasn't the pack-in, though, or I might never have even got GB Tetris, and while Mario got me in the door, Tetris kept bringing me back. I still think that's the best version of Tetris around.
Dragon Quest 9 is a DS game. There are also remakes of 4-6, and various spinoffs (Monsters, Rocket Slime, etc) on the DS.