Taxi Driver is a masterpiece on loneliness and psychological damage. Travis is a very conflicting character. He’s obviously not well, he lacks social awareness and he’s racist. Yet we’re still locked in on his journey. The film is tragic and disturbing. I’d say it’s Scorsese’s best film. I would also recommend another Scorsese film by the same writer, it’s called “Bringing out the Dead”. It stars Nicolas Cage. It’s sort of a companion piece to Taxi Driver. Also excellent!