I had trouble with yellow cakes coming out mealy and dry, (like a dry, oily cornbread texture) then I found this recipe in July 2008 Gourmet magazine. It's simple, easy, and the texture is, well, like cake ought to be - moist and tender. All that and delicious too!
Don't over beat or it will be tough and try to start out with the ingredients at or near room temperature. Of course, you can make this into cupcakes or 13 x 9, just adjust the baking time. It's done when a wooden pick inserted in the center comes out clean. I'll never go back to the box mixes!