Well, since Ed posted up a list of his NES collection, I figured I'd follow that up with something somewhat similar... so, let's take a quick look at all of the games I have for my Gameboy and Gameboy Color.
1)
Super Mario Land (GB) - A classic Gameboy game in it's own right, just as Super Mario Bros. was on the NES. Has a classic theme that differs from your standard Mario theme song, and isn't heard much in new Mario games. The gameplay is pretty similar to Super Mario Bros. on the NES, but the levels are all new, making this a great new experience for any Mario fan out there.
2)
Kirby's Dream Land (GB) - The first Kirby game ever. It helped introduce new gameplay mechanics such as eating your enemies and spitting them back out, which was later used in Super Mario World with the re-introduction of Yoshi.
3)
Tetris (GB) - Probobly the most well-known video game ever! Created by Russian designer Alexey Pajitnov, it helped make puzzle gaming popular, and defined the genre as we know it today.
4)
Metroid II: The Return of Samus (GB) - This one is interesting in that it is a direct sequel to the first game on the NES. While not having the easiest controls ever, it spawned a lot of new ideas for the series that would show up more polished in
Super Metroid for the SNES.
5)
Qix (GB) - A lot more famous for it's arcade counterpart, Qix is a solid puzzle-action game where you try and take over a certain percentage of the screen without getting hit by the enemies. This Gameboy version is a solid port, even with the limited graphics.
6)
Mortal Kombat (GB) - Once again, more famous for it's arcade counterpart. However, this version of MK is the worst ever! Of course, I don't see any way you really could port over MK to the Gameboy. I'm actually just surprised that this version exists! Also, I'm not really sure what that smegma on the cartridge is...
7)
Pit Fighter (GB) - Here we have another bad port of a fighting game. Pit Fighter is a lot more popular on the Genesis, and for good reason. I think if I was forced to play this game forever, I'd rather kill myself! Fighting games just don't work on the Gameboy.
8)
Toy Story (GB) - Sticking with the theme of console ports, we have another one here in the form of
Toy Story. While not a horrible port, I'd still prefer to play the SNES or Genesis version of the game.
9)
Snoopy's Magic Show (GB) - This one is a bit obscure, but I was pleasantly surprised with it. While it's not an amazing game by any means, it has a simple charm to it. You play as Snoopy and the game consists of you collecting all of the Woodstocks on screen, and dodging the bouncing balls. It's simple, and perfect for a handheld game, not to mention the music is infectiously cheery.
10)
Alleyway (GB) - A pretty solid Super Breakout clone for the Gameboy, it provides a classic breakout experience. No power-ups, no crazy techno music. Just some simple breakout. The weird part is, at the beginning of the game, you see Mario JUMP INTO YOUR PADDLE! So... Mario is INSIDE YOUR PADDLE, there is a little Mario head next to your lives counter. So, technically, this is a MARIO GAME!!! MADNESS, isn't it?!
11)
Wario Land: Super Mario Land III (GB) - Sticking with the theme of Semi-Mario games, this game is the first to introduce Wario into the big book of Mario fiction. It includes an overworld map, that looks oddly similar to the one from Super Mario World. Playing as Wario, you put on different hats to get different powers, and you try and collect as much money as you can, Wario being the greedy little guy that he is.
12)
Mario Tennis (GBC) - While all of the other Mario Tennis games were simply "Tennis with Mario characters", Mario Tennis on the Gameboy Color is a completely different experience, and I personally think it's a much more enjoyable one. You play as a new recruit as a Tennis school, and you can level up your stats. The graphical style reminds me of Pokemon, and the gameplay, between the exploration parts, and the actual Tennis are both fun and satisfying. For anybody who's ever wanted to play a Tennis RPG, definitely check out Mario Tennis for the Gameboy Color.
13)
The Legend of Zelda: Link's Awakening DX (GBC) - Last, but most definitely not least, we have Link's Awakening DX for the Gameboy Color. Taking everything that made the original game so great, and adding some new features, and a new dungeon, this game is a must own for anybody who has a Gameboy Color. Definitely one of my favorite Zelda games ever.