During "We Built This City/Too Much Time on My Hands", after Dennis Dupree learns that the Bourbon is going to be torn down because it "no longer generates an adequate tax revenue".
Lonny: That's why I keep telling you - we need to bring back Naked Jello Wrestling Thursdays. But this time, check it: we let women enter!
Franz: I'm not gay....I'm GERMAN!
Early in Act 1 (can't remember which number), some of the ensemble members are doing a group number as Hertz and Franz walk by, and Franz runs off and joins them in their dancing. Especially funny with how the ensemble is clad in "rocker"-type clothing while he's wearing a business suit.
Most things involving Stacee Jaxx are pure funny. Especially when the two bruisers temporarily provide totally deadpan backing vocals during "Wanted Dead Or Alive," causing Constance to give them a WTF look.
Out of the blue, Stacee stops that very musical number for a split-second, long enough to answer a girl's crossword puzzle. "Dalai Lama."
The in-universe Executive Meddling to a band to take it from metal to hip hop. Bad hip hop. It must be seen to be believed, like every poser pushed into one band.
During "Anyway You Want it" when Drew is put in his new wardrobe, he's got a truly crushed look on his face, singing in a hilarious deadpan.
The entirety of the phone conversation between Stacee Jaxx and the poor guy picking up the phones at Rolling Stone late at night. Jaxx's dialogue is this drug-addled, cryptic mess, and the other guy snarks his way through the whole conversation.
And Stacee finding out he "has a gig" that night—cut to the empty phonebooth.
And then when he gets to his gig right after the crowd finishes the big We Built This City/We're Not Gonna Take It number, he recognizes the mayor's wife as one of his old groupies. And pretty much melts her credibility along with her.
When Jaxx goes back to the Bourbon Room to find Constance, he spots her and starts walking to her—only to be ambushed by an adoring fan who pulls him into a ridiculously long kiss. As it goes on, Jaxx turns from his usual response, to holding up a hand in the "just gimme a minute" gesture (Constance answers with an "it's okay, I'm sure you get this a lot" gesture), finally ending up just staring incredulously at the woman kissing him, clearly wondering if she ever has to let up to breathe before he finally manages to free himself.
Every single cutscene in the entire game. Also, when you successfully mow down the door of your enemy's castle, they scream like a little girl and when they get rolled over, all you hear is *PPHHHRRRRRRP!* at the results screen.