I have been cooking and baking since I was a small child, and have only found two products I could not make.  Despite numerous tries, and various recipes, fudge was always a flop.  I found "foolproof" fudge was not;  and "no-fail" fudge did.  Fortunately, I eventually found one recipe that is virtually impossible to ruin.  This recipe results in real candy--  not something you will need to drink.  

The ingredients:

one can condensed milk

3 cups baking chips--  chocolate, or other flavor of your choice

one teaspoon vanilla

How to prepare it:

Line a square baking pan with aluminum foil.

Place the milk in a large saucepan, on low to medium heat.

Add the chips.  Stir gently until they are completely melted and blended into the milk.

Remove the pan from the heat, and add the vanilla.

Pour the mixture into the baking pan, and place it in the refrigerator.

Allow it to refrigerate for a few hours, and then cut it into small squares.  

Store unused fudge in an airtight, covered container--  not in the refrigerator.  

Variation #1:  If you like nuts in your fudge, you can add some chopped nuts before you refrigerate the mixture.

Variation #2:  If you want two different flavors, allow the first layer to refrigerate until solid, and then prepare and add a second layer;  refrigerate immediately.  While you can use whichever flavor chips you prefer, I've found one layer of milk chocolate chips and one layer of butterscotch chips to be especially good.