We have a 'brain teaser' on our Intranet. It's really dumb, and I once submitted an answer that was correct, but not the answer they were expecting, so I didn't get credit. I've been bitter ever since.
I discovered that they get the questions off the Internet (duh) and don't bother to change names or words. So now when the new brain teaser shows up on the Intranet, I email the link to the answer to everyone I know.