This contains(to the best of my knowledge) the complete, original Galoob Codebooks for NES, SNES, Gameboy, and Genesis/Megadrive Game Genies, and modified versions of the online archives for Game Gear. I transcribed the original Gameboy codebook and some things missing from existing galoob.com Gameboy archives myself, and have looked through the SNES codebook, and modified it to more accurately fit the original codebook.

Galoob Game Genie Codebook Collection

Additionally, there are now scans of all the Gameboy Update Booklets:
Volume 1, No.1
Volume 1, No.2
Volume 1, No.3
Volume 1, No.4
Volume 2, No.1
Volume 2, No.2
Volume 2, No.3
Volume 2, No.4

Booklet Scans
Hosted courtesy of GSHI


Updates:
February 17th 2009:
Finally got my hands on some of the update booklets I was looking for. I checked them all out, added the text to the download, and also have a link to scans of the booklets, for those interested.
August 29th 2007:
Went through all the GBGG codes I have on a letter-for-letter basis, and updated some of the files to fix errors, and make codes more consistent. Replaced the Codebook.exe file with a folder containing the same codes and files in HTML form. It also now links to the correct site. The files should be easier to browse, and the compression rate is up by 1/3 of a meg without the EXE's overhead.
February 25th 2006:
Found and added some missing galoob updates to the NES and SNES files. I reformatted the NES file with line breaks between games, so it'll be similar to the SNES file in that respect. Fixed 2 codes, and minor formatting trivialities in the NES codebook.
February 22nd 2006:
Added notes to the SNES handbook, where they were missing. I used Galoob's handbook to check every available note, and fill them in as shown.
February 16th 2006:
I added correct codes for Beetlejuice. The book had them entered wrong. I also fixed some errors with the NES book. NES Play Action Football had 2 code entries with unneccesary duplicate codes in them.
October 19th 2005:
Added Galoob's online Game Gear codes. They're not the original files, because I fixed some minor code errors, and added '-'s where there were spaces in the codes, so the codes would be easier to use in an emulator.
October 17th 2005:
Spell-checked the SNES Game Genie collection file.

Updated SNES Galoob codes from the original Codebook:

Fixed numbering errors in entries with new codes(left inaccurate numbering if the entries matched the book)
Added '-'s where some codes used a space.

Code-wise...
Updated:
Beavis and Butthead, Bugs Bunny in Rabbit Rampage, Flashback, Teenage Mutant Ninja Turtles IV--Turtles in Time

Added:
Romance of the Three Kingdoms 3: Dragon of Destiny

Moved:
Tecmo Super Bowl

September 28:
Updated the gameboy files GBCD0.txt(the original codebook file), and GBCD_upd.txt. Fixes include a missing code from Boxxle, and minor text repairs on Beetlejuice, and Wheel of Fortune code descriptions.