I messed around with boxed cake mix until I came up with this slight variation that makes a BIG difference (at least in my opinion).
Easy White Cake
1 box white cake mix (I use Pillsbury Moist Supreme Classic White)
2 oz Low Fat Cream Cheese at room temperature
1 cup water
3 large eggs
Basically you are making a box cake mix omitting the oil called for on the box and substitutting the cream cheese.
Start with cream cheese in bottom of bowl then add the cake mix, water, and eggs. Blend until moistened then scrape the bottom and sides of bowl. Mix on low speed for 2-3 minutes. Scrape bottom and sides of bowl again to ensure all cream cheese is incorporated. Pour into prepared pan(s) and bake according to times indicated on box.
You will never bake a cake mix without cream cheese again.