Best British film, that doesn't actually feel, or seem British? I didn't think it was a great film anyway. Extremely average. The core essentials that make a film a great film are missing. I'm sure you can think of them. As far as film noir goes, it didn't feel authentic. It's more of a very watered down James Bond film. Unlike most film noir, it failed to engage my attention. It picks up towards the end, but then it's just a few guys running around in a sewer not really up to much.
I'm hoping some reader out there would be so kind at explaining why this is considered a classic, great film, hailed as one of film noir's finest. I wouldn't even call it average, I think the plot was extremely poor, making the rest of the film (considering its genre) irrelevant and most of the dialogue being in German didn't do much either. This section seems to make the film sound fairly interesting, but again it those camera angles weren't well received at the time. I didn't even notice them. Looking on IMDb the film again is regarded by critics and the public as 'flawless'. Must be missing something.
I'll raise your 'Third Man with Lady From Shanghai.