I may have mentioned this before, but I think a diary of your life, as much as you can remember, is a great idea. The good & the bad. (well, some of the bad). Especially things about you, like stories you never told them, would be a great thing to leave your kids.
I started one a long time ago. But the first wife found it, and read some about some of the things I did after we met. And it got thrown out. I sure wished I had that back. I think it was over 50 pages of stuff.