I just bought a couple of old sh*t bikes. A Centurion Time Machine (in every sense of the word) and an Allegro Club Tour. The frames are in good shape, save for the paint. The parts on the TM are pretty beat while the CT is in decent condition.
The Allegro will be my beer grabber/commuter so I'm not really investing too much into it. Hence the skateboard deck cut down to make a rack! Maybe I'll turn it into a ghetto cyclocross racer or something. It has 27" wheels though so that may limit what I do with it.
The Centurion I'm torn on what to do with it. I can keep the paint and upgrade what needs replacing, or I can repaint/polish it and add a nice newish group and wheels. The paint is rough but it has that '80's tackiness to it. After seeing some of the repainted classics on here I am tempted to go that route.
I have a pristine Bianchi with mostly original parts as well. That one won't be molested except for a new bar, tape, and saddle.