Inexpensive ($280 shipped) and light (24 pounds) is my Downtube Nova. It has rim brakes, but they work great for the speeds I ride. The gearing seems a little high for my tastes so I put on a freewheel with a 11T gear. The original was 14T. Cost $28. I bet most casual riders wouldn't care.

I bought it and also the Downtube FS8 ($329 shipped? I forget) this year. The FS8 is 8-10 pounds heavier but offers full suspension and also has better gearing for a little higher speed. It's the only bike I own that has a rear suspension. Very comfy.

I originally thought the Nova would fit in my miata trunk, but now plan to put a hitch on it and use a rack for my regular bike. Both fit in our Jetta wagon. They will be packed for weekend trips where we want to have bikes w/o the
hassle of having them stored on a rack.