I've made microwave fudge (chocolate, chocolate/peanut butter) a couple of times this year and it's worked out surprisingly well!

Ingredients:

• 16 oz semi-sweet or bitter-sweet chocolate (I use the mini semi-sweet since I think they melt easily); I've also substituted part of this with peanut butter chips to make PB fudge and a friend has used peppermint extract and Andies mints for mint fudge
• 14 oz (1 can) sweetened condensed milk
• 1/4 cup butter

Microwave 1 minute, stir, repeat until smooth.
Poor into foil lined (I spray it with non-stick spray) pan.
Chill

I've also added marshmallows in and/or topped with more chocolate chips