The old man loves these he's got quite a few scattered about the south if you want something in particular

The early ones, L reg etc. are terrific value for money now and the later spec, newer shape ones are cracking cars, especially the 220cdi

the early c180 isn't great on fuel but they're pretty bomb proof although the build quality on some of them isn't what you'd expect [alot of them are now built under license FOR mercedes, not directly by them ], but then you're paying mondeo money now

personally, value for money wise, the best is a N/P/R reg c250 diesel make sure its the elegance derivative or the avantgarde iof you can find one