The VW bug is a good vote, tons produced, sold world wide, air-cooled, and cantankerous! They are getting expensive though, seen half ass examples sold for 3-4 grand...they barely cost that new! But then some Magnums are going for close to 2 grand, so maybe not that far off?
I think VW Bug wins this one.
The Yugo is another good one, but you can't find them anymore, at least not where I live, not that I would own one, would rather take my chances with a Bug than an old Fiat design!
Ive learned that Yugos get no respect. Cool looking cars in my opinion but then again my taste in autos sucks to most people. I hear they arent worth much but ive yet to ever actually see one forsale and i go to alot of junkyards.