Though I am a biased owner, I would go with Gilly on the "modern" reliable Benz being the humble C230 (aspro especially). It's M111 gasoline engine is very tight, and I've seen plenty of "runs-like-new" high mileage examples. One potential sore point is the 722.6 tranny, but I'm now seeing high mileage examples of that too, and they seem to be pretty tough once sorted out properly.
The 2.3L versions have no wiring harness issues like 94-95 cars. The M111 head gasket seems to have no relation to the M104 gasket - they don't leak.
Our 1998 C230 has been bullet-proof. My neighbour's ES300 isn't one bit more reliable.
But, for the loooong haul and the ability to keep the car on the road with a modicum of expertise and expense, I'll stick with my original statement concerning the 240D.
1998 C230 "Black Betty"