The end of "Another Birthday": After spending his birthday feeling dejected and unwanted, the green pig with the birthday hat returns to the pig pen with the others at night, the lights go out, and then the piggies wish the birthday pig a happy birthday!
The end of "Cordon Bleugh," where the pigs discover that Matilda's cooking (which the other birds had turned down, finding it inedible and causing her to cry) is utterly delicious. The smile on Matilda's face is the cherry on the sundae!
"Joy to the Pigs" is also heartwarming, as Terence delivers presents to all of the good pigs in the kingdom.
"The Portrait" from the Stella episodes features Willow forced to paint a portrait of Gale. During this time, she also helps out an artist pig who's making his own portrait. After Gale shows disgust for the pig's portrait and breaks the pig's paintbrush (leaving the poor guy in tears), Willow hands the pig her own paintbrush. The pig happily responds by giving her a small cuddle.
In "Off Duty," when the other birds fail to protect the eggs while Red took a much-needed break, Red, seeing how guilty his buddies feel, not only forgives them but invites everybody (including the eggs) to join him on vacation.
When Chuck saves Red's life in "Chuck Time" and Red shows his gratitude with a quick but sincere hug.
In "Sink or Swim," it's a real treat to see the gang having fun in the ocean, but the real heartwarmer is when Red sinks like a rock and Chuck and Bomb immediately dive down after him, and Red wakes up on shore to find everyone gathered around him to make sure he's all right.
In "Spaced Out," when Chuck finds himself the butt of yet another of the Blue Triplets' pranks, this time he just brushes it all off as Actually Pretty Funny.
The end of "Clash of Corns," when Bomb gives Matilda a sweet little kiss on the cheek before the two of them share a rainfall of popcorn.
In "The Truce," even though it's obviously a trick, it's rather touching to see Chef Pig go to all the trouble to provide Red, Chuck, and Bomb with a delicious gourmet lunch and to see the birds happily tuck into all their favorite things.
In "Party Ahoy," after King Pig misses out on the big party on the next island, Chronicler Pig and Professor Pig invite him to join their little tea party.
In "Eggshaustion," Chuck's reaction to seeing the eggs smashed is nothing short of heartbreaking...and his relief at seeing them in one piece and okay will bring on the warm fuzzies in a truckload.
In both "Slingshot 101" and "Do As I Say," Red and Matilda learn the same lesson: to lighten up and take some time to just be Oneofthe Kids.
Let's face it, the birds' sheer dedication to the safety of their eggs truly warms the cockles of the heart. The eggs are their babies; every bird is more than willing to go through hell (and back) to protect them, and is it any wonder those birds get so livid every time those greedy little piggies try to turn those defenseless babies into gourmet omelettes?