In Season 6, Episode 13, "And Maggie Makes Three," Homer Simpson (voiced by Dan Castellaneta) tells his kids the story of how the family's youngest, Maggie, came to be. At the time, Homer left the nuclear power plant to work his dream job at a bowling alley. After celebrating, Marge (Julie Kavner) discovers that she is pregnant and tries to withhold the information from Homer. He eventually finds out and is distraught, as their financial plans are now ruined. He tries his best to get a raise from his new job but fails to do so and gets his old job back. As punishment, Mr. Burns (Harry Shearer) leaves a plaque in front of Homer's desk that reads, "Don't forget, you're here forever."
When Maggie is eventually born, Homer immediately falls in love with her. Back in the present, Bart (Nancy Cartwright) and Lisa (Yeardley Smith) are still confused as to why there are no photos of Maggie in their family album. Homer responds by saying that he does have photos, but they're kept somewhere where he needs them most. We then see the wall in front of his desk at work is plastered with photos of Maggie. The photos are set up in a way that they alter the words on the plaque to now say "Do it for her."
It's easy to forget through all of Homer's dim-witted antics that deep down, he loves his family and works hard to provide for them. Any parent who has fought tooth and nail to provide for their loved ones, even if it means working a less-than-ideal job, can immediately identify with this moment. And even if you aren't one, the pureness of his connection with the most innocent member of the Simpsons household is just too wholesome to not get choked up over.
