I have this 1991 Murray Spectra. Probably the most dangerous bike in this thread. It cost me $15, and about every part that can rattle or squeak rattles and squeaks. If I shake the handlebars the entire back end of the bike wiggles around separately. I rode it to the store the other day...a very scary experience.

Although it will probably kill me, I like it. It shifts great, it's nearly rust free, and it's much faster than my mtb w/slicks.