From 1d4chan

Tic-Tac-Toe is a very, very, simple game where two players alternate between placing X and O on a 3 by 3 grid, attempting to be the first to get three in a row. Excluding rotations and reflections, there’s less than 800 possible game states. Even the most remotely competent players will result in a tie if they actually give a damn, and it has become the classic example of a “solved” game as a result. The movie War Games would famously use it as a metaphor for the The Cold War's concept of Mutually Assured Destruction, proclaiming "Such a strange game. The only winning move is not to play."

See also Tiktaq'to

Board Games
Classics: Backgammon - Chess - Go - Tafl - Tic-Tac-Toe
Ameritrash: Arkham Horror - Axis & Allies - Battleship - Betrayal at House on the Hill - Car Wars
Clue/Cluedo - Cosmic Encounter - Descent: Journeys in the Dark - Dungeon!
Firefly: The Game - HeroQuest - Monopoly - Mousetrap - Snakes and Ladders - Risk
Talisman - Trivial Pursuit
Eurogames: Agricola - Carcassonne - The Duke - Settlers of Catan - Small World - Stratego - Ticket to Ride
Pure Evil: Diplomacy - Dune (aka Rex: Final Days of an Empire) - Monopoly - The Duke
Others: Icehouse - Shadow Hunters - Twilight Imperium - Wingspan