I fell in love with
German-engineering 
because of an Audi... and then discovered MB.
Aside from the obviously arguable factors of
quality ,
performance , and
prestige , I stay with MB because of the timeless
beauty. Unlike other luxury alternatives, it fits my visual and tactile preferences - knowing that I will still love the way it looks and feels in +10-years. MB aesthetics withstand the test of time and fickle fads.
The MB heritage is authentic. I find most of the competitor offerings to be precise replicas of "luxury" yet lacking visceral soul. There is nothing ersatz about MB luxury.
Cheers,
- LGV
2009 S550
1992 300E (sold in 2008 with 240k miles)
1985 190E 2.3 (sold in 1995 with 130k miles)