Ha! In Chernobog's vein of "Ug. So embarrassing I actually wrote this that it must be destroyed!": I used to write loooong vampire stories.
Like, super melodramatic crap. And every character had this really elaborate, gothic way of speaking. And they'd all give like, page-long speeches about pretty much nothing. These things were like, 200+ pages long, written in notebooks (it was before I had a computer). It was ridiculous.
I found them when I was 18 or so, puked in disgust, and threw them out. I wish I hadn't! I do still have some older writing from them days, and it's hilarious. Ah, teenage angst!
I think I saved about 90% of my writing from the old days. There are some embarassing stories here and there (I came up with "troglins, creatures that can control the living, turning them into zombies, who then send these zombies in armies of a million or three to attack border castles" and the way to get rid of them was to dig a huge hole in front of the castle, use fire spells to direct them towards it, wait for them all to fall and then set them on fire… while still being alive!) but overall quite a lot of them have some pretty smart ideas which I've been salvaging for my scripts :D
Sadly, I lost almost all of my comics that I drew between the age of 5 and 12 (there was like couple of thousand pages total).