if you're looking for exclusivity, forget them all and go for a W124 500E
that having been said, i would have to agree with norman on all points. the addition of other criteria will certainly change the results.
Personally I'd go for the C36 first. Simply because I have first refusal on one owned by a family friend should they ever decide to sell. the C43 doesn't really interest me much at all and i like the C36 aerodynamics package better.
as for the C32, i MIGHT consider getting one in a few years when they start hitting the secondary market with reasonable prices. however forced induction is not particularly attractive to me and, I prefer the smoothness of a straight six. if i want a car to be rough and raspy, i'll drive my 2.3-16.
if i were in a position to buy a car right this minute, i'd opt for the 190E 2.5-16 EvoI and EvoII simply because of the rarity of the cars.