I always laugh at the part where Arthur laughs sharply after Randall makes the bad joke about Gary and then stops abruptly.
And of course when he kills Randall, and Gary can't reach the security chain.
And I always laugh at the part where he shoots Murray.
Many other moments. The moment where the records guy realizes who he is and they just stare at each other. The subway shooting.
I found moments to be very Jokeresque in their macabre and it makes me laugh to see how they hit it on the head so subtly. It's a funny freakin movie in the darkest possible way.
Part 2 looks equally hilarious already.