pretty much every bike I've bought but don't still own.
v-strom 650. my first bike. completely reliable, but completely boring to me. it got me from A to B, but it was just another mode of transportation to me.
Triumph Sprint ST 995. great engine, but I could not ride more than 100 miles on it without feeling like I was being tortured.
Honda XR650L. Every time I rode it for more than 40 miles, I had to stop, take my migrane meds and lay down for two hours before I could ride it home. Seriously.
R1150RT. It was like riding in a car, with no windows. I didn't feel like I was on a motorbike.