In 'Great, now if my girlfriend reads this I'm going to have to learn how to hack Sonic the Hedgehog or risk getting turned down' news, Redditor Equinn0xX hacked a Contra cartridge to propose to his girlfriend. Curse you, Game Genie!
This is how I did it. In short, I bought Contra, dumped the ROM, hex edited the file, flashed it to a new ROM chip and soldered it all back together. Took some work but worth it. I changed player names to ours and also changed the ending text to ask her once she beat the game. She said yes!
Cool. But you know what would have been even cooler? If the marriage proposal was accessed via Konami code. Actually, wait -- NOBODY STEAL THAT. I came up with it, I get to use it first. Just kidding, I'm dying alone, have at it.
Hit the jump for the proposal screen, the Frankenstein'd game cartridge, and a shot of the lovely couple dressed as Rainbow Brite and Shredder.