Preceding my 2014 FX, in my stable was a '98 Honda Superhawk VTR-1000, a '04 Ninja ZX-6R streetfighter w/ dirtbike handlebar, and a '00 SV650 Naked.
The VTR was the main instigator of my Zero buy, with how it fervidly drank gas. Loved the curve-twisting torque on that thing (80 ft/lb), but my FX hits the same sweet spot. Sold it first, before I got the FX.
The ZX-6R had that frantic high-horsepower bite that I really liked; it took me quite a bit of pondering to finally decide on selling it. The $400 valve adjustment job plus the need to upgrade its handlebar (necessitating more money for new cables, etc) pushed me to sell it. My next bike will be a SuperSport-type electric bike, hopefully. Would love more than 115 hp next time. Sold it 3 weeks after I got the FX.
The SV, I still have. It's for sale. I'm okay with not selling it immediately - it's a damn good bike.
Really, the recent sudden desire to stop burning oil helped me deflate my gas-burner stable and start preparing for an electric stable. It'll be a decade until I can have pickings from the used-ebike market, which I'm most sad about.