High up in the list we find the highest placed handheld game 'The Legend of Zelda: Link's Awakening'. It's a brilliant game, more than worthy of the title "best handheld game ever made", yet sadly often overlooked. The original release on the GameBoy is already sufficient for a place this high in the list, but the 'DX' version on the GameBoy Color a couple years later, makes it complete.
It is a very original game for the 'Legend of Zelda' series, where Link, the same Link from 'A Link to the Past' and the 'Oracle' games, is shipwrecked during a storm at sea and finds himself on an unknown island populated by people and talking animals, as well as strange foes. As the story goes on, and not only for a Nintendo game is this one very story-heavy, hints and events allude to a greater mystery that surrounds the island.
This game still amazes me. It is a GameBoy game, but it is one seemingly impossible to have existed on the system. It runs circles around it's "big" console brother released a year earlier in every way and I am not at all bummed by the fact that I have bought this game four times on three different devices. What's also mostly unknown however is that this game actually pioneered much of the series' mainstays. Mini-bosses, bosses with multiple radically different stages, a guide-character, musical instruments with different songs, fishing and collect-a-thon and trading sequence sidequests all started with this game. A truly amazing one at that.