Very common question, but you have to align your priorities before picking a tire. There is no such thing as "the best" tire because those priorities are different for different people.
Longevity?
Fuel Economy?
Noise?
Ride Comfort?
Performance?
All season or summer performance?
Handling in the rain?
That said, both Michelin and Continental are OE suppliers to MB and are on all of the approved lists. But even at that you still have to decide if you're leaning more for performance or longevity.
And, of course, do a search. There are numerous threads on tires and I doubt much new can be added to what is already there.
You can also look at the ratings and spec systems at Tire Rack, they have a pretty large database of information there, all free for the reviewing. Plug in your car, pick some tire parameters, dial in to a few that look promising, then read the reviews, etc. Wherever you buy them, that's a terrific resource, and it's free.
Good luck and enjoy the ride!