Especially the "impromptu salon in honour of the death of Bohemia".
Mark: And Roger will attempt to write a bittersweet, evocative song... *Roger starts playing Musetta's Waltz* ... That DOESN'T remind us of Musetta's Waltz.
Especially Mark's capitulation of Mimi's contribution, which creates...quite the image.
Mark: Mimi Marquez, clad only in bubble-wrap, will perform her famous lawn-chair handcuff dance to the sound of iced tea being stirred. (In the movie, Mimi's expression and pose as he says this is the icing on the cake)
The following exchange in "Life Support" when Mark goes to a Life Support meeting with Angel and Collins yet does not want the others to think he is HIV positive.
Mark: Sorry, excuse me- oops!
Paul: And you are?
Mark: Oh, I'm not- I'm just here to- I don't have- I'm here with— Maaaarkk, Mark! I'm Mark! Well, this is quite an operation.
Adorkability Levels Rising: At the beginning of Tango: Maureen, Mark quickly advances on Joanne and spontaneously busts out with some of the most jarring, awkward dance moves imaginable. She looks startled and backs away slightly.