Byron making it back to his family, and running into their apartment building.
Florence telling Richie, in her own way (she's possibly suffering from dementia), that Richie is her favorite grandson. Richie reminds her that she's talking about him. Florence happily replies "I know!"
Later in the film, Richie opts to go save his grandmother even against the warnings of his Jerkass parents. Which ultimately saves his life and Florence's.
Also, the slightly Ship Teasey interactions between Richie and Taffy the First Daughter at the end.