A child's birthday: a party... or a headache?

Birthday parties for our beloved toddlers are festive occasions that can quickly turn into a headache. Should we bake a gluten-free, sugar-free homemade cake or buy a chocolate cake from the local supermarket? And when it comes to activities, is a sack race enough, or should we take the little ones to the circus for a pony ride, social pressure be damned?