Linking to an old post, my favorite mix: Magnolia Mixes Gluten Free Lemon Pound Cake Mix - details in the post

My favorite from-scratch: Gluten-Free Chocolate Cake, a recipe I got from runpunkrun, though I can't remember where and I don't see it posted here. Uses GF flour; it and the accompanying frosting recipe can be adapted in a number of ways, including dairy-free and vegan, and different presentations, including cupcakes.