I love the old black and white Gameboy and its games!
Some of the best Gameboy games I had the opurtunity to play and recomend was, Tetris, Gargoyles Quest (adventure,rpg something), Super Mario Land 1 (the second and the third are not as good but still great), Qix was cool, Kwirk was cool to but wasnt really my type of game. Shockingly I liked Golf a lot! even though I hate sportsgames.. I even made som hole in ones in Golf.
The Zelda game was considered the best GB game at the time, but its shurely not the best Zelda, but its still great, and has some impressive graphics for a black n white gameboy.
Stay away from Turrican though, its not that good on GB.