I've taken brief trips on a variety of bikes, and while I was always glad to be on 2 wheels, I didn't much like the ungainliness of the BMW R1200GS I've ridden, to say nothing of every plodding large metric cruiser (Vulcans, Boulevards, et al.) I've set butt upon. The Harley XR1200 was kinda vaguely fun, but not in an I'd-ride-that way. I didn't care for the rattletrappy, cheap-feeling, peaky-motored older Japanese pseudo-sports like the EX500 and the Katana, but it's possible that the ones I rode were in such poor repair that it detracted from the experience.
For all that, it's just inherently fun to be on 2 wheels, though.