There are at least four for me in Clannad:
1)When Nagisa breaks down during their school play due to discovering her parents' past and thinking she ruined their lives only for Akio to come and encourage her telling her she's their future and it doesn't matter
2)When the wedding ceremony takes place at the school in After Story and pretty much everyone shows up thanks to Fuuko's efforts with the stars for who knows how many episodes
3)The whole episode after Tomoya and Ushio meet, both when Nagisa's parents are talking at night and when he goes to visit his father after so long.
-Bonus for the Tomoyo After scene where they meet at the snowy hill.
Pretty much all of these left a strong enough impression for me to remember throughout the years and I will always remember them as they're really nice about portraying the importance about family and bonds no matter what shape they take.