Even Family Guy has missed opportunities when it comes to plot.
- A lot of fans have noticed that Chris' art talent could have led to some great episodes and side-plots that the writers never take advantage of.
- After being introduced in "He's Bla-ack!", one would think that this would open the door for interactions between the Griffins family and the Tubbs-Brown family, the episode in which they return even teasing some interaction between Rallo and Stewie, and later Chris. However, Rallo, Roberta, and Cleveland Jr are all severely Demoted to Extra and hardly receive any lines, with Roberta being the worst offender as she has yet to speak any lines in the show at all. The only member of the Tubbs-Brown family to get any attention in the show is Donna, who mostly just exists to be Cleveland's wife.
- In "Road to Germany", we learn that Mort's grandparents were Polish Holocaust survivors who got married the day the Nazis invaded. The story of their survival is one with a lot of potential, but instead it was forgotten in favor of Stewie, Brian, and Mort figuring out how to get home.
- "Stew-Roids" wastes two: Stewie growing large muscles and Connie getting Hidden Depths and/or Character Development.
- "Not All Dogs Go to Heaven" was the episode that had appearances from all the major actors of Star Trek: The Next Generation, kidnapped by Stewie and forced to spend the day with him. This amounts to a few minutes worth of scenes at most in which they go through a McDonald's drive-thru and go bowling. The episode is mostly about Meg becoming a born again Christian and trying to demonize Brian for being an atheist.
- The "Life Of Brian" arc ended two episodes after it began and didn't explore the mystery of who ran over Brian Griffin. It had the potential to be a great murder mystery plot, but ever since Brian was brought Back from the Dead, his killer will never be known.
- Brian's storyline in "Meg Stinks", where he's forced to live outside after being sprayed by a skunk, plays a fairly prominent role in the episode's first half, but ends up becoming almost forgotten in the second half of the episode.
- The plot of "No Chris Left Behind" involves Chris trying to fit in at a fancy school, which offers plenty of opportunities for jokes. However, a major chunk of the episode is dedicated to the series' overly long chicken fight gag, and the rest of it focuses mostly on the family trying to find ways of paying for Chris's fancy education, essentially turning the main conflict into a subplot.
