Satine: Oh, Harold, nobody could play [the Maharajah] like you could!
Zidler:(jovially) No one's going to.
The entire scene between Christian and Satine in the elephant.
Toulouse: He's got a huge talent!
And the Call Back later when the Argentinean kisses Christian:
Argentinean: Nothing funny, I just like talent!
Christian (believed by the Moulin crew to be the Duke) attempting to wake a fainted Satine by shaking her, which Zidler sees through his telescope as... something else.
Zidler: Right on target!
Satine attempting to smuggle Christian out of the elephant while distracting the Duke.
All the "Like a Virgin" scene.
The unconscious Argentinian falling through Christian's ceiling. Followed by a dwarf dressed as a nun.
Especially with Christian's utterly deadpan description of exactly that happening. Complete with the Aside Glance that breaks the fourth wall, freeze frame, and typewriter bell.
The scene where everyone pulls wool over the Duke's eyes and improvise as Christian reinvents the whole Spectacular Spectacular!
It crosses over into Awesome territory when you realize that because it is improvised, no one had any chance to plan, compare notes, or anything—and yet somehow they all manage to contribute and create something that not only meshes, it tells a good story and convinces the Duke to sign on as their patron. While undercut by what happens with the Duke later, at that moment you can't help but smile along with him because of how well and audaciously they pulled it off!