Double Indemnity (1944)

It's definitely hard to pin down a personal favourite Wilder film, though I tend towards his earlier masterworks such as 'The Lost Weekend', 'Sunset Boulevard'...and THIS. He was one of the finest at getting straight through the bullshit and to the heart of all things noir (as the immortal Jean-Luc Godard stated, 'All I need to make a film is a man, a girl and a gun').
Barbara Stanwyck is one of my favourite actresses of the period, and is a classic 'femme fatale'. I've never been a huge fan of Fred MacMurray, but his 'nice guy' persona is used to sheer advantage by Wilder, and he end up both doing his finest work for Wilder (here and in 'The Apartment') and being the ultimate noir male protagonist. Interestingly, one of my favourite actors, Edward G. Robinson, thought so much of the script that he opted out of his demand of never doing a supporting role. Many people admire Wilder the director, but as a writer (or co-writer) he's just as cinematically important and influential.
Like any other film of his, at least that I've had the pleasure to see, it's worth a purchase and re-watches. The dialogue, especially, is simply fantastic. I'd take just one of his early works over a hundred of the films Hollywood churns out nowadays. They're simply that better and intrinsically satisfying. Immortal cinema.

So poor old Tom Powers is married to the cold and calculating "Phyllis" (Barbara Stanwyck). When she starts to have an affair with his charismatic insurance broker "Walter" (Fred MacMurray) the two alight on a cunning plan to dispose of him and to claim the life insurance money. Being in the know about these things, "Walter" figures out a way in which they can double the payout. With their hands still rubbing together, the man's body is found on a railway track and when the police believe it accidental, the cash rolls in. All looks good until one of his colleagues "Keyes" (Edward G. Robinson) smells a rat - and he starts to stick his very sensitive nose in. I always felt Barbara Stanwyck was a very under-rated actress - she is terrific here, as is the under-stated Robinson. Even the usually unremarkable MacMurray turns in an strong performance as Billy Wilder, with some great intense photography and wonderfully potent dialogue pulls the threads of this clever and menacing drama together. The always reliable Miklós Rósza creates a score that really works well with the accumulating tension as we head towards a denouement that keeps us on our toes right til the end. This is a great film.