Nobody is perfect... not even your favorite '90s shows.

While "Friends" stole our hearts and "Family Guy" had us howling with laughter, between the heartbreak and the side-splitting these classics sitcoms were making a few mistakes. Ever notice the major continuity error in "The Simpsons" opening credits? How about that blown storyline in "Will & Grace"?

In case you missed the mess-ups in your favorite '90s sitcoms, here's a gallery to get you up to speed. As usual, all photos are courtesy of MovieMistakes.com.