Well, the thread about unused characters didn't go very far, so how about another one - how about story titles you'll never use? I've been looking through files from hard disks dating back to the early 90s and found a lot of fascinating documents, things I certainly don't remember ever writing. One was a text file with story titles. Here's a couple; if one of them grabs you, it's yours!

The Mystery of the Scarlet Snowman

Pies and Spies and Alibis

A few more:

Starswarm of Doom

The Dark Angles of Elsewhen