Just found the easiest way to add a nice label inside the chart.
CenteredTextMarker label = new CenteredTextMarker();
label.Text = text;
//just dawing a line with one dot tall in the same position you want the label to be
plotter.AddLineGraph(compositeDataSource1,
dptLine,
label,
new PenDescription(ComponentName));
and I'm Hiding the legend and build a customized one my self by doing
plotter.LegendVisible = false;