All my bikes are niche bikes..and I have been lusting after a fat bike which would be nice in the winter. Actually ridden at this point are a Brompton, Xootr Swift, Surly Steamroller, 82 Holdsworth Special, 92 Cannondale mtn bike and a old Centurion Accordo setup with studded snows and low gearing. Recently read an article by Jan Heine in his blog in which he praises the return of the all purpose bike which can be used for road, touring, single track etc. If I could have only one it would be something like that although I would certainly miss my current bikes.