Zelda DX - Basically a color remake of Link's Awakening on GB, but it has got an extra dungeon to explore in it..
Zelda Oracle Series - If you did play Links Awakening, then Oracle of Seasons and Oracle of Ages are two totally new color GB games you can play through..
Super Mario Bros DX - Super Mario Bros and the (Japanese) Super Mario Bros 2 (aka the "Lost Levels" in US and Europe), all rolled into one, packed with some neat extras..
Spy Vs Spy - Not the kind of game considered a Nintendo classic, but it's humerous and good ol' fun on the go. I recommend you try it out
Wario Land 3 - Yet another good Nintendo handled gaming experience for the GBC.. I would also suggest you try get Wario Land 2 (which was also sold seperately in Monochrome anyway), but the color version of the game dont work on GPVGB.. for me at least
R-Type DX - "5 games in one!" Well, to be honest it's a bit of a lie, as 3 of those games are essentially the same with changes (your main lot is R-Types 1 and 2 in color, with the monochrome versions thrown in seperately and a "R-Type DX" game merely being both put together). Still, this is a decent GBC game.
That's just about all I can think.. I probably know more, but I cant remember all for now.. :blink: