“Let's never try to get even with our enemies, because if we do we will hurt ourselves far more than we hurt them. Let's do as General Eisenhower does: let's never waste a minute thinking about people we don't like.”

Source: Say What You Will

Often attributed to Stalin, there is not a single source which show that Stalin said this at any given time. There is only one source outside the blogosphere which attributes the quote to Stalin, but does not provide any evidence for the attribution. That source is the book Quotations for Public Speakers : A Historical, Literary, and Political Anthology (2001), p. 121 by the former US senator Robert Torricelli.
Misattributed

Letter to Sisters at Saint Mary's, 1848.

Presidential campaign (April 12, 2015 – 2016), 2016 Democratic National Convention (July 28, 2016)
Context: Tonight, we've reached a milestone in our nation's march toward a more perfect union: the first time that a major party has nominated a woman for President. Standing here as my mother's daughter, and my daughter's mother, I'm so happy this day has come. Happy for grandmothers and little girls and everyone in between. Happy for boys and men, too – because when any barrier falls in America, for anyone, it clears the way for everyone. When there are no ceilings, the sky's the limit. So let's keep going, until every one of the 161 million women and girls across America has the opportunity she deserves. Because even more important than the history we make tonight, is the history we will write together in the years ahead. Let's begin with what we're going to do to help working people in our country get ahead and stay ahead.

Source: The Moon and More

Source: Dictionary of Burning Words of Brilliant Writers (1895), p. 420

Introduction to Treasury of the Free World (1946)

Remarks During Signing of Defense Bill http://www.guardian.co.uk/world/2004/aug/06/uselections2004.usa2 (5 August 2004).
2000s, 2004