I suddenly cannot save a ListLinePlot (with a legend) as a PDF without it also saving the indicator "Out[.] =" also there. This is really strange since I've been saving them all along (by highlighting the cell and using "save selection as" without it showing, then suddenly out of nowhere, this "Out[.]=" started appearing? I never even closed the notebook. Could it maybe have something to do with having done a Clear["Global`*"]?
Simply right-click the plot and choose Save Graphics As... Do not select its cell bracket and use Save Selection As...! Just right click the plot itself without selecting anything.
If the plot has a legend, select both the plot and the legend with the mouse, as if they were text. Make sure that the cell bracket is not selected. Now right-click and use Save Selection As...
As an alternative to both, use
Export instead of the GUI method.