I need to plot serial data from Arduino.

I require support for:

1. Various data formats (e.g. signed, unsigned, 8 bits, 16 bits);
2. Plots several data on the same axes;
3. Exports / Imports file data.

As plotting serial data from Arduino is a common need, my question is:
What programs/utilities are available for plotting serial data from Arduino that meet the needs above?

What are the advantages / disadvantages of the method you have suggested?