First off, I DON'T want this to turn into an argument about whether or not it's ethical to use science this way. I personally don't know what side I'm on with cloning. This is about what you would do if you had a clone, an exact copy of you. I think it'd be more fun than a problem.
Pros:
You'd always have a person to play a game with.
Mario Kart: Double Dash!! would go VERY smoothly.
Someone would always be there for you to talk to, even though it's talking to yourself.
You wouldn't be able to get on each other's nerves, since you know what you like and dislike.
Think about it, you could share drinks and toothbrushes... technically, even without a clone you're sharing it with the you of two minutes ago/yesterday.
Card games would be possible to fairly play since the cards are drawn at random.
You'd have half the chores and split the homework (heads odds, tails evens.)
You wouldn't fight over music or TV since you have the same interests.
You could sit by yourself on the bus to keep the freaks away from you.
Cons:
Single-player video games. You COULD take turns, like "You be on the Fungi Forums while I play, we'll switch in an hour..."
Multiplayer games would depend on items to determine who wins.
Going somewhere? "Shotgun!"
You'd always have to have a coin to flip for decisions since rock-paper-scissors would never work.
Any contest would result in a tie. Staring contest, hold your breath, art contest, running (considering that the track is the same), anything.
Since you'd think the same way, you couldn't April Fool yourself.
What kinds of things woul you and you do?