The pep pills episode of Saved by the Bell did have the fun lines "I'm so excited! I'm so excited! I'm so, so... I'm so scared." And "Theres no time, theres never any time. I don't have time to study. I'll never get into Stanford."
The " Very Special " episodes from 90's sitcoms,where at the end, the cast are gathered together to talk to the audience about the message of the episode.
The Fresh Prince did a joke about this one episode. They had done this for real but one episode about Will taking Poetry class for a girl they had it end with the cast gathered around reading a poem and end with Will looking at the camera and saying something like "If you want to read more go to a library" or something and then laughing and saying just kidding.
I'm sure its probably mentioned, but in old sitcoms they used to do a lot of episodes where the characters are locked in some place like a garage or a basement (basement was a big one) and can't get out the entire episode. There is also stuck on the ledge, or parents (family) going to elaborate lengths to teach the child a lesson. Spending lots of money, playing pranks or acting/pretending. The Cosby Show playing a drinking game, making Rudy drink "alchohol" to freak Vanessa out. Rearranging the entire house and pretending to be different people to show Theo what living on his own would be like. Home Improvement doing similar things, Rosanne playing expensive pranks on each other even though they were a poor family. Etc.
I said to my brother than I would hate living in the Cosby house because they always did that to their kids.
The flashback episodes are pushed by the studio who want more episodes from the show but want to spend less money and want it done faster. So they fill out the season with a flashback show because its cheaper. Thats what they said on the Simpsons commentary.
How about a character in the show, a main character, doing something so horrible to another person like lie about who they are or something, only to reveal the truth and (in real life) the person wouldn't forgive them and would be so upset they would never see them again but in the show they forgive them and all is ok by the end of the show. But usually the person, a girl friend, isn't seen again on the show.
And that reminds me of the girlfriend guest star episodes. Where the main character like Will on Fresh Prince or Zack on Saved by the Bell have new girlfriends every episode almost and go through some major story with them like Zack realizing not to judge her by her appearance and they make it seem like she will be around for a while, and then she is gone.
Or a character on a show getting a girlfriend but since she isn't part of the main cast, or in the opening credits, you can tell she or he wont return. It wasn't until Big Bang Theory where guest girlfriends ended up staying to become part of the main cast.