Besides the Zelda oracle games and colorized original GB games.
I barely bought any GB color carts. It only lasted 3 years then GBA came out. What did I miss? Any really good ones?

pokemon (gsc and puzzle challenge), zelda dx, mario dx, that's about all i played.

Super Mario Bros. DX and Mario Tennis are pretty good.

Super Mario Bros. Deluxe. So much content for a GBC game.

I had a GameBoy Color with no Gameboy Color games D:
Just Color-less gameboy games....

The only game I had for Gameboy Color was Pokemon Red. Other than that I dont know of too many Gameboy Color games.

Legend of Zelda Link's Awakening DX
Super Maio Bros Deluxe
Donkey Kong '94
Pokemon Crystal

Metal Gear Solid was pretty awesome.

ALERT (looney toons) was awesome (kinda hard), but you needed a second cartridge to continue the game, it was very dissapointing, when you grew up and finally were able to beat the couple hard parts, the game wasn't available... _

_EDIT

Apparently it was a direct and spirtitual sequel, but I still would've loved to play it

Dragon Warrior 1+2 and 3, probably some of the best RPG game play you could get on the handheld (apart from Pokemon of course).

I did recently get to try the original Shantae so that's another one. Man I hope they put that on 3DS VC someday!
It's hard to believe how polished and fancy it is. I bet even the Nes couldn't have pulled off a game that detailed.

Now now, people, don't forget the Game and Watch Gallery games!

I thought Megaman Xtreme 2 was pretty good. Pokemon Pinball was kind of fun. There were a couple of Pokemon games on it (that were pretty good) but unless you want to play them in their original form, you'd probably be best playing the remakes.

^I forgot all about Megaman Xtreme! Boy, I really hope we get those on VC. We're getting the gameboy Megamans eventually so not that farfetched.

Bionic Commando: Elite Forces

Shantae
Metal Gear Solid
Dragon Quest I and II
Wario Land 3
Zelda Oracle of Ages/Seasons
Pokemon Crystal
Bionic Commando: Elite Forces
Dragon Quest III
Zelda Link's Awakening DX
Donkey Kong Country
Mario Golf
Blaster Master: Enemy Below
Crystalis
Survival Kids
Megami Tensei: Last Bible

I'm sure if they're the best... But they are in my personal list...

-TLoZ: OoS/OoA
-Wario Land 3
-Harvest Moon GB (1, 2 and 3)
-Wario Land 3
-Pokemon Silver/Gold/Crystal
-Wario Land 3
-Pokemon TCG

Those are the ones i can remember i really enjoyed and would love to play again.
I bet there are more but i can't remember the names right now.

_{Did i mention Wario Land 3?}

Pokemon Crystal.

Only GBC game i had rest of the main series were original GB titles...

Survival Kids was ace — precursor to the Lost in Blue games, but with more item creation and monkeys. Really good and very addictive!