Cool stuff you've found with used games.

I just bought a used copy of Out of this World for Genesis on amazon because it was really cheap and it was one with a case and manual. To my delight I found that the manual actually had writing in the 'notes' section of the tattered manual. Since the game is on a password system, there were a bunch of codes for specific parts of the game listed. The best part is that there are a stretch of codes in the middle that have descriptions like 'in a cave', 'deeper in the cave', and 'more caves'. 
 
I also bought WWF No Mercy used at a gaming store and there were a bunch of hilarious custom characters made.
 
Did anyone else find cool stuff related to their used gaming purchases?
 
edit: we can broaden this to borrowing games and renting them too!

I once bought a copy of Sonic 3 with all the save slots used with the game beaten and the emeralds collected on each save. Needless to say I would have loved to talk to the original owner.

" I once bought a copy of Sonic 3 with all the save slots used with the game beaten and the emeralds collected on each save. Needless to say I would have loved to talk to the original owner. "

Don't know if this counts but I bought a used memory card for the gamecube so I could play games on my wii (very long time ago) and there were a bunch of good saves on it including 100% completion in super smash bros melee which was all those trophies and such.  I also found a used gameboy in the food court one time when I was a kid and took it.  But other than that the coolest thing is that their cheaper.

I bought Ocarina of Time and the dude who played it was almost done.

My friend borrowed OOT from some kid in college and when we finally plugged it in he had done the 3 heart challenge and only had like 2 deaths. I mentally hi5d him

A full sized city recreating all the race tracks of Super Mario Kart on a used SimCity for the SNES. I don't know who did it or who the time to do it, but kudos to him for such a great work of art.

Wow, this is cool. I never really considered used games could have so many awesome memories attached to them. I do remember once renting a wrestling game to find all the main wrestler's had been altered to look totally ridiculous. I wasn't amused.

" Wow, this is cool. I never really considered used games could have so many awesome memories attached to them. I do remember once renting a wrestling game to find all the main wrestler's had been altered to look totally ridiculous. I wasn't amused. "

Haven't found anything fun :(

I bought a cheap copy of Pokemon Pearl once and it had a TONNE of legendary Pokemon on it.

I don't think i've ever gotten anything cool with my used games. I bought Warioware Touched from a guy on Ebay once and it came in a pizza box.... So that was.... interesting...

I once had a cool bootleg GBA cartridge from "Nintondo".

Pretty much 90% of my video game collection ;)

I bought Alan Wake used and it had the Free DLC code inside. Awesome.

Oddly, my friend bought Castlevania Chronicles for the PSX and when it came the amazon seller had put the manual and the manual for Symphony of the Night in the jewel case.