Here is a fun new one that I tried. I thought it really improved the cake mix and made it yummier and fancier. From the Lion House Bakery book.
1 chocolate cake mix (I have also tried it with yellow and it was yummy)
1 can cherry pie filling
Preheat oven to 350. Grease a 9x13. Combine ingredients with a large spoon (a mixer will break up the cherries). Spread batter into pan and bake 30-40 minutes.
1 c sugar
1/3 c milk
6 T butter
1-2 cups chocolate chips
1 tsp vanilla
While cake is baking, combine sugar, butter, milk in a saucepan. Bring to a boil over medium-high heat, then boil for 1 minute, stirring constantly. Remove from heat and add chips and vanilla. Stir with a wire whisk until smooth. Pour over warm cake and spread evenly.