The good news is that with this chart of optimal Tic-Tac-Toe moves, you'll never lose another match. The bad news is that this would've made War Games a whole lot less suspenseful.
I admit it took me a second to to get the hang of reading it, but once you do it's a piece of cake. I feel like I'm memorizing blackjack plays, just with no foreseeable financial benefit. [xkcd]