Which elections were the most significant in their outcome??? Which election is still a source of controversy and debate...

Presidential Elections
1960
Many still think Nixon won and Kennedy Stole it, think of 2000

1968
The US was burning and the democrats were done and the Law and Order Nixon Won

1980
The Dominance of Regan starts and Jimmy Carter reputation is destroyed.

1992
The republican dominance ends and Clinton takes control

2000
Closest and most controversial election of all time likely and started the Era of Bush Jr.

Other
1994 Elections
The Republicans start their dominance
2006 Elections
Republican dominance ends.


In Canada....

1968
The most popular and controversial leader (Trudeau) takes control for 16 years and changes the country for better or worse, Likely what Kennedy reign would have been like...

1984
The election is noted for having the most famous Television moment ever (you had an option sir!)
It was a conservative triumph...

1988
Free Trade rips the country part and all signs show that Mulroney who was seen as being the Ronald Regan of Canada was losing his grip..

1993
This is the best election ever and is something of legend in Canada.
The Conservatives win only 2 seats out of almost 300 and a man who cannot speak English properly rules Canada for the next 10 years. The Liberal Dominance begins for the next 14 years.

2006
The Conservative take control and Canada is now a divided partisan nation for the first time since 1993.

Are you limiting this to the last 50 years or so? Because I can name a few others in American history which were very controversial and troublesome...

yes because I don't many know about US presidential history before FDR.

The elections of 1932, 1896 and 1860 were quite significant I think.

1860 by a mile. Think today's "partisanship" is bad?