I would choose a '92-'93 500E. Although I own a '92 400E (80K), which I love, the 500E is the ultimate "wolf in sheep's clothing". I love the flared front fenders, among other things the 500E has to offer. I have a friend with a stock 500E who told me that he once raced and outran a Ninja bike from a stoplight.
I also like 300SEL 6.3, 300CE, and 230/250/280SL. Finally, my first Mercedes, a 1980 300SD (sold w/ 249K) was nothing fancy but absolutely trouble free for the entire time I owned it.
'92 400E (80K) black
'80 300SD (sold w/ 249K)