Pretty much the whole ending: Jay and Silent Bob offer Dante and Randal the money to buy the Quick Stop; Dante proposes to Becky; and Dante and Randal buy, fix up, and re-open the Quick Stop together.
The final scene.
Dante: Can you feel it?
Randal: Feel what?
Dante: Today is the first day of the rest of our lives.
Zoom out on Dante and Randal starting one of their Seinfeldian Conversations as the picture fades to black and white and Soul Asylum's "Misery" starts playing. They actually started playing the song in the store, which caught Jeff Anderson (Randal) completely by surprise and made him start crying on the first take. You know it's a crowner when even the actors get emotional over it.
When Randal tells Elias that once Dante leaves, he'd be his new best friend. Consider how much of a Jerk Ass Randall was to Elias, it really says something.