The Watergate Scandal has defined Richard Nixon's legacy as a former President. Despite the fact that he was elected twice, served six full years and successfully extracted us from an unpopular, protracted and expensive war, he will always be remembered for his spectacularly bad judgement regarding this scandal.
Not that I feel this is undeserved, it was a criminal act by a President who had come to believe that he was above the law. He deserved impeachment had he not resigned, but as a historian, I have to acknowledge there were other important and positive things he did during his Presidency.
The Clean Air and Water Acts were passed on his watch, and he aggressively pushed for integration of schools through busing, which was unpopular at the time, even if socially necessary. He successfully drove a wedge between two adversaries, the Soviet Union and China through detente, and locally, where I live, he gave Mt. Adams to the Yakama Indian tribe as sacred native land.
Despite all of this and anything else he may have achieved, he will always be, first and foremost, associated with the Watergate Scandal and the other unconstitutional acts that came before and after it.