In "That's My Mommy," Quacker confuses Tom as his mother, despite Tom's efforts to eat him. When Quacker realizes this, he decides to throw himself into boiling water because his "mommy" wanted that. Despite this, Quacker says, "I still love you, Momma" and jumps into the water. It is at this point that Tom has a change of heart and saves Quacker from a boiling death. The two hug as Tom streams tears down his cheeks, and the cartoon ends with the two quacking at each other in a duck pond.
Made even more heartwarming by Tom, one-half of the greatest Silent duo in history, gives out a Big "NO!" before he saves Quacker.
The endings of "The Night Before Christmas" and "Snowbody Loves Me" Basically the same thing—Tom makes Jerry stay out in the cold, but rescues him from freezing to death.
There's an episode similar to those where, Tom kicks Jerry and a puppy Jerry had taken in out the house. During the night, a severe thunderstorm kicks up and Tom feels guilty for what he did, worrying that Jerry and the puppy could drown in the flood. He goes out to find them, only to be swept away by the flood waters. Jerry and the puppy (who were safe), find him and bring him back to care for him. When Tom wakes up, he then gives the puppy milk and the puppy calls all his friends to share with them. Tom (and Jerry) just looks on happily.
There's an episode where a woodpecker hatches and believes Jerry is its mother (because its egg rolled into Jerry's home). The bird irritates Jerry and he eventually kicks it out, but when Tom goes after it, Jerry saves it multiple times. Then, when its real mother comes to get it, it flies away with her, leaving Jerry sad until the woodpecker returns to give Jerry a kiss and Jerry then happily waves goodbye. Aww.
At the end of "Heavenly Puss", the moment Tom hugs and kisses a confused Jerry is just too sweet (and kind of funny).
Then there's "The Cat and the Mermouse", where Jerry saves Tom from drowning.
In "Tom and Jerry Meet Sherlock Holmes", after Jerry is grapped by the henchmen, Tom springs into action to save him.
In "Tom and Jerry Meet the Wizard of OZ", when Miss Gulch takes Toto away from Dorothy, Tom and Jerry were incredibly saddened by this and what do they do about it... they fixed a makeshift bike and went after Miss Gulch and managed to save Toto. Lesson learned from these movies... It's never a good idea to upset BOTH Tom and Jerry!
The ending of "Little School Mouse" is both hilarious and heartwarming — all through the cartoon, Jerry has been acting as a teacher to Nibbles (complete with blackboard and pointer) teaching and testing him in the ways of cat-outwitting. Nibbles has managed to pull off most of the tests, though generally (and to Jerry's increasing frustration) through kindly asking Tom to comply. The final test is to tie a bell around the cat's neck, which Nibbles solves by gift-wrapping the bell and giving it to Tom as a present. Tom loves the present, puts it around his neck and is thrilled with Nibbles's kindness. The final scene has Nibbles as the teacher, now teaching a grumpy Jerry and a smiling, enthusiastic Tom that cats and mice should be friends.
"Mouse In Manhattan". Jerry ditches Tom because he's bored of country life and heads to New York City. The end of the episode has Jerry running back to the relative safety of his old home, and kissing a confused Tom (who never read the goodbye note Jerry left.)
The song between Robin Hood and Maid Marian in Robin Hood and His Merry Mouse.