As with any model of any car the best ones tend to be the last/later years because the problems have been found and worked out. I have been considering a W140, but I am leery of the cost of repairs as my 1999 E300 has robbed me plenty, itself. My thoughts on a W140 are to look for a later year and simpler overall (i.e. fewer gadgets). So I am looking for a S320 or possibly S420 of 1995 or newer. To be the idea of a 600 sounds cool, but then am I willing to feed it money. I want the ride and drive and for that I do not need something to close the door for me.