TicTacToe : http://jsbin.com/nuxum/25/edit

app.js

var app = (function () {
  "use strict";

  /*
  Game Settings
    0 = blank
    1 = player 1
    2 = player 2
  */
  var current_player = 1;
  var turn = 0;
  var board = [
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0]
  ];

  
  var elem = {};
  elem.btn1 = document.getElementsByTagName('button')[0];
  elem.msg = document.getElementById('message');
  elem.space_0 = document.getElementById('space_0');
  elem.space_1 = document.getElementById('space_1');
  elem.space_2 = document.getElementById('space_2');
  elem.space_3 = document.getElementById('space_3');
  elem.space_4 = document.getElementById('space_4');
  elem.space_5 = document.getElementById('space_5');
  elem.space_6 = document.getElementById('space_6');
  elem.space_7 = document.getElementById('space_7');
  elem.space_8 = document.getElementById('space_8');

  var spaces = [
    [elem.space_0, elem.space_1, elem.space_2],
    [elem.space_3, elem.space_4, elem.space_5],
    [elem.space_6, elem.space_7, elem.space_8]
  ];

  
  
  
  var renderMessage = function (msg) {
    elem.msg.innerHTML = msg;
  };

  var renderValue = function (val) {
    if (val === 0) return " ";
    if (val === 1) return "x";
    if (val === 2) return "o";
  };

  var renderBoard = function () {
    var i, ii;
    for (i=0; i<board.length; i++) {
        for (ii=0; ii<board[i].length; ii++) {
          spaces[i][ii].innerHTML = renderValue(board[i][ii]);
        }
    }
  };
  
  var gameStatus = function () {
    var b = board;
    // Across
    if (b[0][0] === b[0][1] && b[0][0] === b[0][2] && b[0][0] > 0) return b[0][0];
    if (b[1][0] === b[1][1] && b[1][0] === b[1][2] && b[1][0] > 0) return b[1][0];
    if (b[2][0] === b[2][1] && b[2][0] === b[2][2] && b[2][0] > 0) return b[2][0];
    // Down
    if (b[0][0] === b[1][0] && b[0][0] === b[2][0] && b[0][0] > 0) return b[0][0];
    if (b[0][1] === b[1][1] && b[0][1] === b[2][1] && b[0][1] > 0) return b[0][1];
    if (b[0][2] === b[1][2] && b[0][2] === b[2][2] && b[0][2] > 0) return b[0][2];
    // Diagonal
    if (b[0][0] === b[1][1] && b[0][0] === b[2][2] && b[0][0] > 0) return b[0][0];
    if (b[2][0] === b[1][1] && b[2][0] === b[0][2] && b[2][0] > 0) return b[2][0];

    // Draw
    if (turn >= 9) return 0;

    return undefined;
  };
  
  var nextTurn = function (player) {
    turn++;
    current_player = (player === 1) ? 2 : 1;
    status = gameStatus();

    if (status !== "undefined") {
      // Game Over
      if (status > 0) {
        renderMessage("Player " + status + " is the winner!!!");
      } else {
        renderMessage("The game was a draw.");
      }
    } else {
      // Next Turn
      renderMessage("It is now player #" + current_player + "'s turn...");
    }
  };

  var markBoard = function (player, pos) {
      var x = pos[0],
          y = pos[1];
      if (turn >= 9) return;
      if (board[x][y] === 0) {
        board[x][y] = player;
        renderBoard();
        nextTurn(player);
      }
      else {
        renderMessage("PLEASE TRY AGAIN.");
      }
  };

  var init = function () {
    // Reset Settings
    current_player = 1;
    turn = 0;
    board = [
      [0, 0, 0],
      [0, 0, 0],
      [0, 0, 0]
    ];

    renderBoard();
    renderMessage("It is now player #" + current_player + "'s turn..."); 
  };


  // Event Listeners
  elem.btn1.addEventListener('click', function(){
    init();
  });

  elem.space_0.addEventListener('click', function(){
    markBoard(current_player, [0, 0]);
  });
  elem.space_1.addEventListener('click', function(){
    markBoard(current_player, [0, 1]);
  });
  elem.space_2.addEventListener('click', function(){
    markBoard(current_player, [0, 2]);
  });
  elem.space_3.addEventListener('click', function(){
    markBoard(current_player, [1, 0]);
  });
  elem.space_4.addEventListener('click', function(){
    markBoard(current_player, [1, 1]);
  });
  elem.space_5.addEventListener('click', function(){
    markBoard(current_player, [1, 2]);
  });
  elem.space_6.addEventListener('click', function(){
    markBoard(current_player, [2, 0]);
  });
  elem.space_7.addEventListener('click', function(){
    markBoard(current_player, [2, 1]);
  });
  elem.space_8.addEventListener('click', function(){
    markBoard(current_player, [2, 2]);
  });

})();

index.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JS Bin</title>
</head>
<body>
  <table>
    <tr>
      <td id="space_0"></td>
      <td id="space_1"></td>
      <td id="space_2"></td>
    </tr>
    <tr>
      <td id="space_3"></td>
      <td id="space_4"></td>
      <td id="space_5"></td>
    </tr>
    <tr>
      <td id="space_6"></td>
      <td id="space_7"></td>
      <td id="space_8"></td>
    </tr>    
  </table>
  <button>Play Tic-Tac-Toe</button>
  <div id="message"></div>
</body>
</html>

style.css

table {
  width:240px;
  height: 240px;
  border: 1px solid #aaa;
  table-layout:fixed;
  cursor: pointer;
}

td {
  border: 1px solid #aaa;
  text-align: center;
  vertical-align: middle;
  font-size: 60px;
  font-family: sans-serif;
}