Tic Tac Toe

3D Tic Tac Toe
Get four in a row horizontally, vertically or diagonally on one plain or across all four plains. Played against the computer. (Java)
http://home.earthlink.net/~cmalumphy/3d.html

4D Tic Tac Toe
Four dimensional version of the game offering five difficulty levels. Played against the computer. (Java)
http://www.geocities.com/ResearchTriangle/System/3517/tictac4d/tictac4d.html

Pig-Tac-Toe
Two player version of Tic Tac Toe game played with pigs. Game requires Internet Explorer 4.0 or higher. (JavaScript)
http://www.yuckles.com/pigtactoe.html

Senor Pobre's Tic-Tac-Toe
Game played against a smart-mouthed virtual chihuahua. (Flash)
http://www.infospace.com/games/game_tictactoe.htm

Tic Tac Toe
Game allows user to specify the height and width of the board, and the number of marks in a row needed to win. Played against the computer. (CGI)
http://boulter.com/ttt/

Tic-Tac-Toe
Game offers two-player, play against computer, or computer vs computer option. Features three levels of difficulty and saved wins. (JavaScript)
http://ostermiller.org/calc/tictactoe.html