Double Indemnity is probably my favourite film noir. Detour and D.O.A. are in my collection too. Chinatown is a more modern neo-noir which I recommend too.
'Batman Returns', a cult classic. Wasn't popular on release but compare it to the Schumacher series and it's a winner. I was annoyed to see five had shown it at 6pm on a Saturday, evidently certain scenes had to be cut.