I'm a one bike guy, but that's not by choice. I've been riding motorcycles since I'm 12 years old and I'm soon to be 61 with a little bit o' luck.
If I comfortably had the room to keep another motorcycle, I would have at least one more in addition to the Beast and very possibly a third. Today's choices would likely be a Thruxton, as machine number two and a sport-tourer to complete the stable... very likely the Connie 14.
Variety is indeed the spice of life and that is why an additional bike or two would be optimal for me. The Rocket III is by far and away the most gratifying and satisfying motorcycle I have ever had, but no one machine can do all of the things that I like to do on two wheels optimally, hence my short wishlist consisting of a smaller, runabout sort of bike and a more deftly maneuverable, go-fast machine that is purpose built for touring.