If you're talking about reliability. I think the older 70s-80s Mercedes, especially the Diesels. I think maybe the best was the 6.9, because of the engine. Have to admit, I don't know that much of the older Mercs. However, even with that much displacement for that time. It beats even a majority of cars today.

-mike
'87 560 SEL (AMG)
'92 400 E