Time Magazine has made a list of the worst cars of all time

1899-1939 

1899 Horsey Horseless
 1909 Ford Model T
1911 Overland OctoAuto
1913 Scripps-Booth Bi-Autogo
1920 Briggs and Stratton Flyer
1933 Fuller Dymaxion
1934 Chrysler/Desoto Airflow

1940-1959

 1949 Crosley Hotshot
1956 Renault Dauphine
1957 King Midget Model III
1957 Waterman Aerobile
1958 Ford Edsel
1958 Lotus Elite
1958 MGA Twin Cam
1958 Zunndapp Janus

1960-1974

 1961 Amphicar
1961 Corvair
1966 Peel Trident
1970 AMC Gremlin
1970 Triumph Stag
1971 Chrysler Imperial LeBaron Two-Door Hardtop
1971 Ford Pinto
1974 Jaguar XK-E V12 Series III

1975-1989

 1975 Bricklin SV1
1975 Morgan Plus 8 Propane
 1975 Triumph TR7
1975 Trabant
1976 Aston Martin Lagonda
1976 Chevy Chevette
1978 AMC Pacer
1980 Corvette 305 "California"
1980 Ferrari Mondial 8
1981 Cadillac Fleetwood V-8-6-4
 1981 De Lorean DMC-12
1982 Cadillac Cimarron
1982 Camaro Iron Duke
 1984 Maserati Biturbo
1985 Mosler Consulier GTP
1985 Yugo GV
1986 Lamborghini LM002

 1990-Present

 1995 Ford Explorer
1997 GM EV1
1997 Plymouth Prowler
1998 Fiat Multipla
2000 Ford Excursion
2001 Jaguar X-Type
2001 Pontiac Aztek
2002 BMW 7-series
2003 Hummer H2
2004 Chevy SSR

http://content.time.com/time/specials/2007/completelist/0,,1658545,00.html