When all the babies see who they think is the Wizard to grant them a wish, instead of wishing themselves home like they wanted, they all look at Tommy and he says "We wish we had our doggy back".
Tommy taking care of Dil, singing him a lullaby after Tommy was previously angry.
And after that exchange, Dil grabs the other half of the blanket (which he and Tommy had previously fought over, tearing it in the process) and gives it to Tommy, showing that Dil has realized how rotten he had been and the two sleep through the rain together.
Later when their parents find them, Dil briefly drinks from a bottle before stopping and letting Tommy have a sip.
A reairing of the film on Nick sometime later featured the cast of All Grown Up commenting on the film. Inevitably, the teen versions of Tommy and Dil are quick to have a sweet brotherly moment after viewing this scene.
Also doubles as a Crowning Moment of Awesome, Angelica's workaholic mother throwing her cell phone in the river after being reunited with Angelica and the babies.
Stu giving Tommy the special pocket watch to show the responsibility his son has as a big brother.
Stu: We weren't gonna give you this until you were a little bit older, but, I think now's the right time. (hands Tommy a watch with a photo of him and Dil inside) Shiny, huh? And Grandpa Lou put your picture inside. I know it's hard, Tommy. You have a little brother now, and that's a big change. (Tommy puts down the watch.) Stu: Uh, Dil can be pretty tough to get along with, huh? But sometimes little brothers, they aren't everything you'd hoped they'd be. (Stu opens a drawer, then pulls out a picture of himself and Drew, when they were kids) That's why big brothers have got to have faith. And one day, you'll see...he'll change. After all, you've got responsibility now. I know I can trust that you'll stick by Dil's side and be a swell big brother. Tommy: [thinking] Sponsatility...
At the end when the babies reunite with their parents, Tommy drops his watch and Stu picks it up, smiling at it being still in perfect shape.
Didi: Oh, Stu! You did it! You found our boys! (Stu hugs Tommy and Dil. Tommy drops his watch; Stu picks it up, still in perfect shape; Stu smiles) Stu: Yeah, I guess I did. (Tommy & Dil hug each other)
Drew forgiving Stu for losing the kids at the end, resolving their more adult mirror of Tommy and Dil's conflict.
Grandpa Lou proudly telling Stu that he has "the Pickles spirit", usually their interactions tend to be more a sense of comedic conflict and about The Generation Gap, so it's nice to see them have a very affectionate father-son moment.
When the adults consort the forest Rangers for help, Ranger Frank is too busy deliriously ranting about the so called dragon he saw to be of any use. Ranger Margaret, however is much more helpful and realizing how serious the situation is, immediately leaves to help the Parents.
The babies reuniting with their parents...Oh, and as for the Monkeys? Their owners also arrive to take them back.
Igor: My little furry comrades! (The monkeys happily run towards the circus masters) Serge: Splendid monkeys! Come to papa! Who's your daddy?
One very happy monkey even kisses Serge on the lips. Awww...
As Chuckie puts it: "The Monkeys founded their daddies!"
Might not Seem Like it, but Drew's argument with Stu at the beginning of the film. Drew was trying to get Stu to get a real job...because in his words he had "No Benefits, No Insurance, and Another Kid on the Way!". In his own way he was trying to help his brother and his family.