I would say that my child preferred (when he was a child) affirmation over the others. He always needed to hear he was loved and demonstrations of love from us. He also wanted quality time which reaffirmed the love from his parents.
My son's is quality time, he is always asking if we can play together. My daughter's is physical touch, she cannot get her day started without some cuddling time. I think it is super important to understand someone's love language to show how much you love them.