The Hollywood actor has appeared in numerous films throughout his long career, including his Oscar-winning performances in Glory and Training Day, but admitted that Se7en (1995) and Michael Clayton (2007) are the roles that got away.
"With Clayton, it was the best material I had read in a long time, but I was nervous about a first-time director, and I was wrong. It happens," he told GQ.
Directed by Tony Gilroy, Michael Clayton follows a "fixer" who is brought in by a law firm to help fix a situation after one of their lawyers has a breakdown, starring George Clooney, Tilda Swinton and Tom Wilkinson.
Se7en starred Brad Pitt and Morgan Freeman as two detective partners hunting down a serial killer who uses the seven deadly sins as his way of murdering people.
Washington also talked about the movie roles he wanted that he didn't get, in Oliver Stone's 1986 Platoon and Stanley Kubrick's 1987 Full Metal Jacket.
"They were like, 'Well, [Kubrick] doesn't send out his scripts'," he shared. "I was like, 'Well, then what do you want me to do?' Platoon, I wanted to play the part Willem Dafoe played."
Washington previously starred in Safe House and has also lined up roles in Flight and 2 Guns.
In the same interview, Washington opened up about his friendship with the late Whitney Houston, calling her death an "example" to him and others.
"It's more of an example to me - or the rest of us - to keep it together," he said. "I was listening to her song 'I Look to You'. It's prophetic."