Deus Ex on the PS2 reformatted my memory card. Formatting was a thing for certain games - for whatever reason, and I did so the first time, carefully moving my stuff from one card to another. After I cleaned it off, I put the shit back on (because, frankly, the other card was a madcatz one and was shit).
After getting halfway, the damn thing asked me again. I said no, it said LOL OKAY YOU CANT SAVE, and I got to the start menu before turning it off.
Booted it up again later that day to play something else, and bam, my card was fucking sweeped clean. Hilariously enough, Deus Ex didn't ask to format. Gee, I wonder why.
Ultima 9 is one huge game breaking big. By far the worst.
RIP DMA Design.
As originally released, the game could not be completed due to several bugs. Although actually four completely unrelated issues, they became known collectively as "The Attic Bug". After the player entered the room The Attic, various rooms would undergo corruption on all subsequent game plays, including all monsters disappearing from The Chapel, and other screens triggering instant death. This was caused by an error in the path of an arrow in The Attic, resulting in the sprite travelling past the end of the Spectrum's video memory and overwriting crucial game data instead. This bears similarities to a buffer overflow, and as such is an early example of such an error and the problems it can cause.
The Attic bug in Jet Set Willy on the ZX Spectrum.
it's quite a fascinating bug :
Another famous one was the corrupt save files in PSO1+2 on the Gamecube. Countless people lost hundreds of hours of playtime as a result.
Turrn around...Battlefield 4:s corrupted save files had me playing the first episode way too many times.