Always display data labels above columns in HighCharts

This seems to be easier:

dataLabels: {
    enabled: true,
    inside: false,
    ...
}

You need to disable crop and overflow, see: http://jsfiddle.net/NKXRk/4/

    plotOptions: {
        column: {
            dataLabels: {
                enabled: true,
                crop: false,
                overflow: 'none'
            }
        }
    },