Both movies have very heartwarming endings. That is, until Kevin is yelled at by somebody.
Kevin talking to Old Man Marley in church, discovering he's actually quite a nice man despite all the scary rumors.
Kevin's mother Kate being comforted by the Polka King while constantly calling herself a terrible mother.
Kevin and his mother reuniting at the end of the first film.
Marley, the old man, reuniting with his son, which Kevin witnesses.
Buzz praising Kevin for not burning the house down while they were gone.
Home Alone 2
Buzz's heartfelt speech/apology to Kevin, he's actually kind of a nice kid, when not acting like a total dick.
The first and second time we hear "Christmas Star". The first showing Kevin missing his family once again while looking at a view of New York at night. What adds to the heartwarming is that he says goodnight to his mother, while at the same time in the Florida Resort Kate is saying goodnight to Kevin. The second time was before he decides to deal with Harry and Marv. He makes a stop at the Beth Israel Hospital Children's wing. Where a sick kid is looking out the window and waving at Kevin, who waves back.
Kevin: You can mess with a lot of things, but you can't mess with kids on Christmas.
Kevin giving the second turtledove ornament to the Pigeon Lady.