Return Maximum value from a JSON Object

simpler can be subjective... Another way to achieve what you ask is to get an array of the values using Object.keys and Array.prototype.map, and use the other solution with Math.max that you linked :

var data = {
    0: {
        'Number_of_Something': 212
    },
    1: {
        'Number_of_Something': 65
    },
    2: {
        'Number_of_Something': 657
    }
}

var max = Math.max.apply(null,
                        Object.keys(data).map(function(e) {
                                return data[e]['Number_of_Something'];
                        }));