Philip Seymour Hoffman, William Macy, Julianne Moore, John C. Reilly, Philip Baker Hall, Tom Cruise, Jason Robards, Melinda Dillon, Jeremy Blackman, and Melora Roberts. Each actor makes a strong contribution with great depth and range to this powerful film. But Tom Cruise gives the performance of his career. Before your eyes he changes from a self-confidant, smartass, egomaniac into a silent, dark wretch possessed by demons. It's a stunning moment.
Cruise delivers an Oscar worthy performance.
I believe we can also look for a few supporting actor nominations. Special nods to composer Jon Brion and songs by Aimee Mann. The camera work of Robert Elswit deserves mention, as does editor Dylan Tichenor. This, however, is P.T. Anderson's film in every sense. If you get the message, we are all passing each other with the same baggage.