I didn’t read all the replies, so there may be some overlap in my list of favorites:
‘Body Heat’
‘The Long Kiss Goodbye’
‘Blood Simple’ (the Cohen Brother’s first film - Stellar!)
‘Laura’
‘Sunset Boulevard’
‘Touch of Evil’
‘Double Indemnity’
‘The Letter’
‘Angel Face’
‘The Postman Always Rings Twice’
‘Notorious’
‘Dark Passage’
‘Leave Her to Heaven’
‘Strangers on a Train’
Great list!
I would add: “The Big Sleep” and “Maltese Falcon.”