[youtube=0tRcQRQ7ntA]Cantonese Trailer[/youtube]
In order of decreasing certainty...

Yan (Tony Leung)... ENTP
Dr Lee (Kelly Chen)... INFJ
Mary (Sammi Cheng)... ENFP
Sam (Eric Tsang)... ESTP
Lau (Andy Lau)... who knows? ISTJ?

But he dresses ENFJ.

Not that there's anything wrong with that.