Cancel all your plans for tonight -- go ahead and cancel your plans for tomorrow too. You're going to be playing Super Mario until you get severe hand cramps.
Recently released Full Screen Mario is a complete remake of the 1985 Super Mario Brothers game, plus it contains "literally millions of possible random maps." And the best part? It's free.
That actually may not be the best part if you can program HTML5, because there's the option to create a level. That's right, a new level of mushrooms and coins designed by you.
Good luck on your quest to get a new high score!