out of those cars I don't think you can go wrong buying any of them.
I personally like the 124 chassis cars, but the 190e is also a very good car, and the w123 diesel is also a great car.
I didn't know they made the 190e 2.3 in 1992 with a 5 speed. I thought they stopped doing th 5 speed in 87-88? and I thought all 190e's after 1989 were 2.6 litre m103 engines.
If it were me looking to make a purcahse on any of those cars, I'd go for the one with the best records, and I'd check to see if the 87 300E has had the timing chain done and valve guides/seals done. if it hasn't then it is probably due for them.
One last thing to consider. How do you feel when driving each of them. the one that gives you the biggest smile is the one I would go for.
hehe
Everytime I get in my car, I smile as I fire up the engine. and I smile more when I drive.
Alon