Ideally a W113 SL
More likely a W114 (250/280C) or W126 (560SEC).
My problem is I don't know where it would fit in the fleet... Right now I have my 99 Civic Si (daily driver which is getting sold soon and replaced), my '93 Civic EX (autocross/ fun car) and my '63 Triumph Spitfire (very long term project). I want/need a truck so next year I am going to buy an old Chevy/GMC or Dodge which will be lowered and one day get a built motor. More then 4 cars is just too many projects/insurance cost. Replacing the daily driver with an old Mercedes might now be the best plan... I think a vintage Mercedes is going to be a car I'd love to own and be able to afford to own but never own like an Alfa.
I have a list of cars or types of cars I'd love to own, a Jag, a Saab or Volvo, a vintage Mercedes, an Alfa and a vintage American car or truck. The Volvo or Saab and Jag are going to be my next two daily drivers and I am aiming to get the vintage truck but how the Mercedes and Alfa fit in I am not sure.