•An episode of Dexter's Laboratory features a rare example of this trope with a female who suddenly turns into an adult woman. Dexter turns Dee Dee into a duplicate of his mother because he has a parent-teacher conference. Dee Dee's immediate reaction is to say "Oooooh..." as she rubs her new Hartman Hips (which produces a glass squeaking noise).
Played with in an episode of Teenage Mutant Ninja Turtles (2012). When April and Casey end up getting their bodies switched, Casey-in-April does take a moment to check his new body out, much to April-in-Casey's annoyance. She gets even more annoyed when she pinches her butt... That is to say, he uses April's body to pinch the butt of his own body.
The Hot Chick has Rob Schneider switching bodies with Rachel McAdams. Hilarity Ensues.
A slightly tamer version appears in the first Scooby-Doo movie. When Fred winds up in Daphne's body, he pulls aside her collar and looks down, saying "I can look at myself naked." The look of disdain that Velma gives him/her is priceless. Then, later, Shaggy takes possession of Daphne's body, however all he does is to admonish her, "Don't you ever eat?"