There's is absolutely no way to claim that any particular MB model is the "most reliable". There may be a few with a gray history, but any that you listed MIGHT be ok IF the previous owners took proper car of their car.

I would look for simplicity. If it' gas you want, I'm not sure what would be simpler than an MB with a 103 motor. Mine has been rock solid.

Next you need to realize that most of the cars you're looking at are 10-15 years of age. You are going to spend $$$ on ANY car that age - asian - euro - domestic - doesn't matter.

Forget the "blue book", especially if you find a mint condition - one-owner car that has been meticulously cared for. That person is going to command top $$ and it's my belief you're better off buying a car like that than one that's full of problems for "cheap". You're going to pay one way or the other. Blue books are guidelines - not gospel.

Finally - there is no such thing as "maintenance free". Maint. is what keeps the car going.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"