I have at least two LJ friends who ride superbikes who will probably get a good laugh from my choices, but remember I'm now too old to control a 1000CC+ bike. Thats not what I need one for anyway, if I wanted a bike that burned as much gas as a Metro Geo I'd get the car!
The Suzuki 250.I can only get in so much trouble on a bike this small, and the one I had ages ago got 90 miles to the gallon, which at the time seemed superfluous at the then 50 cent a gallon fuel cost, but today it makes a big difference. The 250 I had in the 80's had a maximum speed of 70 and I can commute on the freeway with this one.
The Kawasaki EliminatorWhat an impressive name for a single cylendar bike with a piston the size of a 35mm film can.....
I could go with the Kawasaki lightweight and probably break 100 miles to the gallon but its nothing I could get on the freeway with, it would strictly be an in town transportation machine. Unless the laws have changed, the minimum size that can go on the freeway is a 175 and this is actually only a 124! It probably can't do much over 55, but then, I wouldn't need it to.