There wasn't much attraction for me to the Buell, but if I had to buy one, it would be either an XB-12R Firebolt or a Ulysses XB12X.
XB12R Firebolt:
XB12X: BMW GS1150 killer.
Unfortunately, there was not much desire for me to own a V-Twin that was engineered 6 decades ago. I'll keep my Japanese inline 4 cylinder bikes.