gistfile1.txt

var t = {'nike': 5};
var brands = [t, 'New Balance', 'Adidas', 'asics', t, 'New Balance', t, 'Nike', t, 'asics'];
var newMap = [];
var quantities = [];
var max = 0;
var maxItem;

brands.forEach(function(item, index, array){
  if(newMap.indexOf(item) < 0) {
    newMap.push(item);
    quantities[newMap.length - 1] = 1;
  } else {
    var q = ++quantities[newMap.indexOf(item)];
    if (q > max) {
        max = q;
        maxItem = item;
      }
    }
});

console.log(maxItem)