Seems like the new ones lose their charm (if they ever had any) really fast.

W123 - 1977-1985 (9 years)
W124 - 1986 - 1995 (10 years)
W126 - 1981 - 1991 (11 years)
W201 - 1984 - 1993 (10 years)

W210 (1996 - 2002) (seven years)
W202 (1994 - 2001) (seven years)
W220 (2000 - 2005?) (six years possibly?)
W208 CLK (1998 - 2002) (only five years)