Thank you in advance!
Here are a few examples, but there are a lot more.
Brazilian President Jaoao Goulart. April 1, 1964 - Refused to impose austerity measures on his people, employed mass land reforms, controlled foreign capital and recognized Cuba. As for how it reflected on the local population, a repressive military regime backed by US dollars would rule for 2 decades and in turn, Brazil would have the largest disparity of wealth on the planet at the time.
Democratically elected Iranian President Mohammed Mossadeq August 1953 Overthrown by both the CIA and British Intelligence services in what came to be known as Operation Ajax. Response to Mossadeq's nationalization of the AIOC. - In the long run, as we all know, Reza Shah and his brutality employing the ruthless SAVAK was not long to last. Ayatollah Khomeini takes power in 1979 Iranian Islamic Revolution.
Guatemalan President Jacobo Arbenz June 1954- Overthrown by US led military coup d' etat as a reaction to the nationalization of the United Fruit Company. An interesting point to note was that the Dulles family who had many positions in the CIA also held a considerable stock share of the UFC. When Arbenz began the agrarian land reforms, UFC executives did not respond too kindly which had major implications within the CIA operation.
As you mentioned, Salvador Allende 1970 Nixon, 2 days after Allendes democratic victory calls for his ouster. "If we let potential leaders in South America think they can move like Chile we will be in trouble. No impression should be permitted in Latin America that they can get away with this, that its safe to go this way." After overthrowing Allende, Augusto Pinochet seized power and proceeded to murder, torture and kidnap over 3000 political opponents.
I think Nixon's final quote there is very indicative of the way of thinking at the time. The Cold War was rampant and anti-communist rhetoric gripped the nation. At this time, violating rights to self-determination for the sake of keeping democracy 'in tact' was not disputed. Like I mentioned, there were many coups instigated or participated by America and the CIA. However many coups were also quite domestically brewed and the CIA played little part. Despite this, many democratically elected leaders had their power stripped at the hands of American intervention and indeed, the irony is not lacking when one steps back and sees the values and morals that the US has claimed to adhere to.