Have you ever corrupted/lost game data?

New Super Mario Bros. Wii.

I lost all of my data up to World 9 and man was I ticked.
 
Due to an error on my laptop all my game data of Spore and Rollercoaster Tycoon 3 got deleted.
 
I lost one of my files on Minecraft once, my first world. Mainly because my laptop liked to suddenly break down, even when I had the highest of protection. Heck, I asked for a new hard-drive, since that one was obviously broken.

Err-Horrible laptops aside, I made the right choice with regards of saving Minecraft worlds, where I copied the file straight out of the saves, so my second world is now safe for future use, and my two other worlds that I was working on in college have been saved too. I've now got three worlds, two survival, one creative. Never gonna make that mistake again.
 
Too many...
Once my GameCube's memory card became completely corrupted all of a sudden, just before I got to the final boss in Luigi's Mansion.

And last year, when I moved from New York to Michigan, a giant mansion world I built in Minecraft was corrupted. I have no idea what happened, but something tells me it was the movers messing something up >:(
 
You should hire assassins to kill them, a know a really good guy
 
Suddenly, all of my data in Mario Party 8 were removed. I have no clue what happened.
 
Well, I had to send in my Wii to Nintendo when Brawl wasn't working at all, and I just kept getting an error when I played it. (which apparently it was because of the "dual layered" disc and stuff) and I had a chance of losing ALL my Wii's memory. Which would suck really bad. But luckily it was still all there.
 
My third-party GC memory card got corrupted many times. And a cheap SD card reader erased everything on my 3DS's SD card.
 
My Star Wars: The Force Unleashed save file is corrupted. I have accidently deleted my Lego Indiana Jones and Super Mario Galaxy 2 game files and had to restart in the past.