A great acheivement for everyone involved. So many memorable and enjoyable scenes. This is what Tarantino is forever aspiring to. Great music throughout, including good instrumental scores and good use of modern (well, not any more) popular music. Sean Penn a superb and very hatable anti-hero, and Pacino as good as ever. Towards the end gets a bit wacky, as can be expected from de Palma (not intended particularly as a criticism).
The plot/acting is frequently unbelievable in little ways. The relationship with a dancer which has inconsistent emotion and is hugely under acted. The murder of a powerful gangster while high on cocaine lacks drama and steam. Generally trips along and maintains interest but lacks any depth of acting.
In 1975, in New York, Carlito Brigante (Al Pacino) is released on a technicality after serving 5 years in jail, out of a 35-year prison sentence. His lawyer, Dave Kleinfeld (Sean Penn), who is also a close friend, has been instrumental in getting Carlito out of jail. When he comes out of prison, Carlito vows never to go back to his earlier life of crime, despite the incredulity of his former contacts in the Puerto Rican community and the drug-trafficking world. Carlito also attempts to get back in touch with Gail (Penelope Ann Miller), a ballet dancer who also performs in strip clubs to make ends meet. The story develops from there.
The film is about redemption or, rather, what happens when a hardened criminal (Carlito) tries to redeem himself and move away from crime, despite all those individuals from his past around him who, directly or not, are still involved in a range of criminal activities. The film is also about lost love and what happens when a man tries to resume a relationship he had with a woman (here, Gail), before he was thrown into jail. These themes are not that original in themselves: they are found in the film 'Heat', for instance.
All the same, this is an excellent thriller and, in many ways, a great classic of the genre. I do not agree that the story is implausible. Overall, it is quite convincing, and the chemistry between Al Pacino and Penelope Ann Miller feels quite real: each one, in his (or her) own way, is lost and drifting, between his (or her) dreams and the harsh reality around them, and each one seeks in the other the help that he (or she) needs in order to escape from their surroundings. The movie is also very good at creating an atmosphere - that of New York, its nightclubs, its gangsters, and so on. Finally, there are some memorable scenes that will stay with you, and I do not want to say any more in order not to spoil the story.
In my view, an excellent thriller.