I’m afraid simple examples don’t tell much, i.e.:
using Gnuplot, Plots
x = 1:10; y = rand(10);
@gp x y
plot(x, y)
On the other hand, it is very difficult to envisage complex examples of sufficiently general interest, able to discriminate against one or the other.
IMHO, the best approach is to try to solve a specific problem (e.g. here).
Or have a look at the example galleries
Specific resources for Gnuplot.jl are here and here, but consider that any other gnuplot example (e.g. the official demos) can be reproduced from Julia.