What bike...? Hard question to answer - for any given day there could be 2 or 3 candidates. I will say that for a long time it was a second generation Ducati 900SS. Now the Ducati (finally got one 6 years ago) is going in trade for something completely different - A BMW G650 Xcountry. Mixed feelings, of course, but I'd rather have a bike I actually ride than one that mostly sits in the garage and gets looked at.
'09 BMW R1200GSA (Rocinante), '78 BMW R100RS Belgian, '07 BMW G650Xcountry, '08 KTM 450EXC, '07 Montesa Cota 4rt, '07 Scorpa TY-S 175, '10 Kawasaki KLX110L, '86 Honda TLR200 Reflex, '78 Husky 250WR