Being that the Gameboy is actually the only Nintendo system I own (because I was given one!) and that my brother owned one when I was a kid I thought I would list my top 10 Gameboy games in no order.
Motocross Maniacs
Chase H.Q.
Robocop
Double Dragon
Dragon's Lair
Tetris
Snow Brothers Jr.
Tennis
Double Dragon 2
Kung Fu Master
Loved my Gameboy which I still have in working order. Here's my ten:
Super Mario Land 2
Sumo Fighter
Batman: The Animated Series
Sneaky Snakes
Revenge of the Gator
Metroid 2
Kid Icarus
The Amazing Spider-Man
Link's Awakeing
Catlevania 2
Some of my favorites are:
Donkey Kong Country
Game and Watch Gallery 3
Metroid II
Micro Machines 1 & 2 Turbo
Planet of the Apes
Pokemon Silver
Snoopy Tennis
UNO