Simplest 2D Plot Program?

["Thomas H. George" <tomgeorge@spininternet.com>]

I want to plot a set of unconnected points at irregular intervals over a 
period of ten years.

I have used apt-cache search to find and try several programs - xgraph 
seems to be the closest to my needs but I can't make it plot large 
points.  They must be there as it will draw lines connecting the points 
but without the lines the points are invisible even with the -P option.

I hope there is a simple Debian program to do this job and I would 
appreciate any recommendations.

Tom George