This question is hard affffffffffffff.... Birthday cake wise I'd say Victoria sponge or chocolate. If you're gonna have a chocolate cake it MUST have chocolate cream inbetween the layers and/or coating it. There's no other way around it. As for smaller cakes (muffins, cupcakes, the sort) I really like vanilla. My favourite kind of cupcake are the iced fairy cakes from Iceland and my favourite kind of muffin is double or triple chocolate with chocolate fudge in the middle.