For plotting complex functions like xsin(x) and tan(x) - x, several software options are recommended, including GNUplot, GraphCalc, and Graph, which are noted for their user-friendliness and functionality. GNUplot is highlighted for its versatility across different operating systems, while GraphCalc is praised for its calculator-like interface. An online plotting applet is also suggested for quick access. Users appreciate the ease of use with Graph, which allows for immediate plotting without extensive setup. Overall, these tools provide effective solutions for graphing mathematical functions.