PLEASE GIVE ME A CATCHY TITLE FOR MY SPY STORY THAT WOULD CATCH YOUR EYE AND MAKE YOU PICK IT UP AT A STORE?

If you intend to publish the books, which I take you do, your initial titles will NOT actually matter that much. Your publisher and agents will most likely change it into something marketable. I personally wouldn't even bother with a title- if it's publishable, you could call it "Spy" and no one would care. Good luck!