The animated Christmas Special was rife with heartwarming moments. Along with a rather emotional scene of Grandma discussing how much she misses her late husband. In one scene in particular, Garfield sums up the meaning of Christmas in a simple sentence: "Christmas: It's not the giving, it's not the getting, it's the loving."
The ending sequence to "Garfield: His Nine Lives" the animated special. Especially when Garfield basically lies to God and tells him Odie is a cat so that Odie would also get 9 lives back as well. Once the two of them have all their lives back, Garfield and Odie dance in a circle, hand in hand before embracing as they are sent back to the universe that is the main canon. Hilariously, God then hints he knew that Odie wasn't a cat, but did that for them because "We've all got to stick together...".
And the sixth life from the same special, "Diana's Piano", detailing the relationship between Diana and her owner. It culminated in the owner performing a concert just for her pet as an adult, and Diana laying down on the keyboard to quietly pass away during the night.
Diana's Owner: It was Diana's testament to her love for my music.
Garfield mourning Odie after he rides a car into a volcano to stop it from erupting. It just shows how much he cared about his best friend.
In the Halloween Special, Odie saving Garfield from drowning. As they reach safety, and exhausted Garfield tells him with complete sincerity, "I owe you one, old buddy", then later thanks him again by giving him his half of the trick or treat candy—"seeing as how you saved my life about eighteen zillion times tonight."