Curve Tracer

Gentlemen,

I've decided a nice project would be to build a curve tracer which
would (because I'm a vintage nut) use a CRT display of an
oscilloscope. From time to time I have these Big Ideas and it could
conceivably become the latest in a long line of my unfinished
projects.

Which curves would be essential to include for a decent, functional
design? I know what the obvious ones are; just wondering if there are
any more obscure ones which would be advantageous to plot. Finally,
are there any additions one could make to a classic curve tracer's
functionality which were omitted from the early designs (modulation
feature at 1Mhz,100Mhz or whatever) for example?

CD.