These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Several from the musical, but in particular is Bitch/Slut/Liar/Whore, which features a duet sung by one person.
Big Lipped Alligator Moment: Okay... exactly when did Melvin gain the ability to transform into a sexy blonde reporter chick, and why does no one comment upon this in the fourth movie?
In some copies of the first film they have Lloyd Kaufman talking about how it's in the original version before he finds Toxie on the street dancing to the Toxic Crusader themesong for money, talking about how he sold everything for crack, and talking about all sorts of other horrible things he does before Lloyd Kaufman starts smoking crack with Toxie and getting hooked.
Dude, Not Funny!: The beginning of part 4 starts of with a school shootout in a special ed class room and was stated to be a reference to Columbine. Which only happened a year prior. Even if it wasn't cracking wise about a recent massacre, mocking the mentally disabled is pretty low no matter what standards.
Funny Moment: Toxie ripping off Frank's arm. Frank manages to deliver a bit of trashtalk before actually noticing (after which he is properly pimp slapped with his own arm).