
De Niro and Scorsese's second collaboration, 'Taxi Driver' may still be the actor's best performance yet. It is not that he became a worse actor after this 1976 film... just that, his portrayal of Travis Bickle was just exceptional. De Niro plays the role of an army veteran who is earning living as a, well, as a taxi driver. We follow Bickle's life as he loses his sanity due to sheer loneliness and insomnia. The protagonist is a deeply unpleasant man, and yet, we cannot help symapathising him for his purposeless life. It is a full-bodied performance in a superbly-directed feature.
It is interesting that most believe that when De Niro and Scorsese meet, it is to make gangster epics. But their top two films, and De Niro's top two performances, have nothing to do with crime lords. 'Raging Bull' is the story of real-world professional boxer Jake LaMotta and once again the Scorsese and De Niro tackle the issues that men face like jealousy and unreasonable rage with a nuance not seen anywhere else.

This might be recency bias, but I do believe 'The Irishman' is the best De Niro has been in decades. Perhaps the best after the next entry. The tale of De Niro's 6-foot-4 inch enforcer for the mafia Frank Sheeran (dubbed 'Irishman' due to his descent), the film was based on the book 'I Heard You Paint Houses' by Charles Brandt, which chronicled Sheeran's life and also his claim that he offed Jimmy Hoffa. The murder of Hoffa, played by Al Pacino in the film, is still one of 20th century US' biggest unsolved mysteries. The film is stacked with iconic performers, and it appears this was the last hurrah of the old-timey gangster movies.

Another Scorsese film, 'The King of Comedy' was a darkly funny take on the celebrity culture and media and is somehow as relevant as it was back when it released (1982). In the film De Niro plays the role of a wannabe comedian who imagines great things and fame for him, but that is all those things are: his imagination.

An epic war movie directed by Michael Cimino had Scorsese playing the role of one of a trio of American soldiers whose lives change after they are enlisted in the Vietnam war.

The first and as yet only collaboration of Quentin Tarantino film De Niro, 'Jackie Brown' had the actor playing a highly non-traditional role for him as an ex-con who mainly listens to his friend Samuel L Jackson's Ordell. He is so into the background that he is hardly noticeable.

The film that made De Niro, well, De Niro, 'Mean Streets' has aged surprisingly well. De Niro was a supporting actor and it was Harvey Keitel who was the lead actor. And yet, De Niro's Johnny Boy, who was something of a mess, was the film's MVP and most entertaining character.

In 'Silver Linings Playbook', De Niro plays the role of an old man (a normal one, not a gangster) who is a huge fan of the Philadelphia Eagles. He has to care for his mentally ill son (Bradley Cooper). It is a role that De Niro does not play often, but as is usual, he nails it.
Again, despite not being the centre of attention, De Niro manages to own the screen in this film. As per this scribe, 'Goodfellas' is the best gangster movie ever made, yes even better than 'The Godfather'.