It´s not about an excercise, you need to stick to a heatlhy caloric deficit. As long as you stay in a deficit, you will loose fat. You cannot spot treat fat, you cannot loose fat just from the belly.
What worked best for me wasn't doing more or different exercises. I was already doing all kinds of belly exercises for years before developing belly fat, and what halted it was cutting sugary drinks, i.e. no more than a couple of glasses of juice, pop, beer in a week.