Cake – the person who decided to put flour, eggs and sugar into a bowl, mix it all up and bake it, needs applauding. Adding chocolate was the cherry on the top.
ARPANET – the person who sold the concept of a worldwide collection of pictures of naked ladies with no clothes onnetwork capable of withstanding nuclear attack to the US military and get funding for it was a complete genius.
Think tech trees. Is the wheel more important than fire? Maybe. Would we have developed the wheel without having fire first? Probably not. So fire wins.