All riders , though I'm seriously considering to stop waving to any Harley riders, they rarely wave back!
It's funny you say this. As a former Harley owner I completely agree with this. When I bought my Harley (which also happened to be my first bike) they told me only wave to Harleys. I have since sold my Harley and own two Ducs. I only wave to sport-type bikes now unless another type bike waves to me and I of course return the favor. I guess I do it this way because I know if I was told not to wave to anyone but Harleys many Harley riders were told the same.