I know the original question had to do with V8 gas power, but since there have been several posts advidsing him to start simpler--like with a six, I got to add my 2 cents.
For simple, reliable MB starter cars, I think the old 5 cyls diesels are the best. There have all the classic MB "feel" and class, and with the "S" class enough presence to satisfy most people. The 5 cyl diesels are simple to maintain with no computer-related sensors that are nearing the end of their reliable life. The proble I have with ANY 100,000 mile+ car from any manufacturer is those complex computer systems. The sensors are just getting to the age where they fail. First its an O2 sensor, then a throttle position sensor, then ... Unlike a diesel, the gas injection system runs in solvent; not a protecting oil like diesel.
IF you can do your own maintenance, I feel the 5 cyl ( 617.XXX) powered cars are the best way to get into the pleasures of MB ownership.
We all know that MB Tex wears like iron, and always look good.
Just a contrary thought........