I am going to say Mercedes 190E
Good ones are going for strong money at the moment.
I have had three and sold my last one for £1300 in 2009. It was in perfect condition and ones in similar condition are going for up to 4k now!
I always regretted selling my last one.
I had a 2.6 manual too which was a very very good car. try finding one now. Most of the 2.6's left are auto's and after driving both, the manual is far better.
I will have another one some day, it was one of the best cars i have owned and i can only see them getting rarer and more valuable
Edited by Ben_O, 14 November 2014 - 08:19 AM.