Pokémon ROMs
First off, you may be wondering what exactly ROMs are.  Here is my answer:
ROMs are playable video games that can be downloaded and played on almost any computer.  They range from GameBoy games to Nintendo 64 games.  The games are run on an emulator, and I have placed my favorites below.  There is a legal disclaimer that you should read first, since I will take
no responsibility if you do anything illegal.

You may also be wondering why I only supply Pokémon ROMs.  That is because I know of so many others that it would take up many pages just listing them.  You can visit emulation sites, some of which are listed below, to get ROMs other than Pokémon.  Most GameBoy and GameBoy Color ROMs are around 1-2MB zipped and 1-4 MB unzipped.  GBA ROMs are about 4-5MB zipped and 16 MB unzipped.
Emulators
VisualBoy Advance (GameBoy Advance/Color emulator)
Download for Windows
Download for Macintosh

Project64 (Nintendo 64 emulator)
Download for Windows
Sorry, no Macintosh version is available.
ROMs

Note: All of these ROMs are in either ZIP or RAR format.  Once you extract them, they will be playable.  For RAR files, you will need
WinRAR.  For ZIP files, I reccomend WinZIP, but WinRAR will work.

Files not opening? Check out
Troubleshooting.
GameBoy/GameBoy Color:
All ROMs are in English unless stated otherwise.

-Pokémon Green (Japanese only - never released in America)
-
Pokémon Green (Translated to English)
-
Pokémon Red
-
Pokémon Blue
-
Pokémon Yellow
-
Pokémon Gold
-
Pokémon Silver
-
Pokémon Crystal
-
Pokémon Trading Card Game
-Pokémon Pinball
-
Pokémon Puzzle Challenge

GameBoy Advance:

-
Pokémon Ruby
-
Pokémon Sapphire
-Pokémon Pinball: Ruby & Sapphire
-
Pokémon FireRed
-
Pokémon LeafGreen
-
Pokémon Emerald (Japanese only - not yet released in America)

Nintendo 64:

-Pokémon Stadium
-Pokémon Stadium 2
-
Pokémon Snap
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