For the cream cheese frosting, this one always works great for me!
2 (8 ounce) packages of cream cheese, softened
1/2 cup butter, softened
2 cups confectioners' sugar
1 teaspoon vanilla extract
Cream the butter and cream cheese until creamy. Mix in the vanilla, and slowly add the confectioners' sugar. If you want to make it chocolate, you can add 1/4 cup to a 1/2 cup of cocoa, depending how rich you want it.
This is such a great recipe; one that I've used so many times, for countless different desserts. It also decorates really nicely, too, if you were planning on fancy-fying your cake.