Generally speaking, all of the models you listed are well-regarded and probably equally reliable.
However, there are two models that stand out as being easiest to work on: 300CE and 300SEL.
They both have the same 3.0 liter M103 engine and are proven chassis with no major issues.
I think it comes down to whether you'd rather drive a medium sized two door hardtop coupe, or a very large four door sedan.
The 300SEL would be particularly easy to work on as the engine bay is so huge. With the 6-cylinder in there, you could practically jump in there to work on the engine.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Last edited by suginami; 11-29-2003 at 02:53 PM.