Scooby-Doo (animation)/Tear Jerker

"Velma: When I said there was someone out there for you, I didn't think...(looking towards the sky) out there."
 * During the opening of Scooby-Doo on Zombie Island, Daphne mentions in an interview that even though she and the rest of the gang eventually got tired of solving Scooby Doo Hoaxes, she still misses her friends. Scooby and Shaggy happen to watch this interview on TV, and admit to feeling the same.
 * The conclusion of Scooby Doo and the Alien Invasion, when Shaggy and Scooby say their goodbyes to Crystal and Amber.

"Velma: Well, that didn't take long!"
 * Suddenly subverted when Velma comes up with a box of Scooby Snacks for them. (The sight of Velma with her glasses askew and her hair mussed up during the tussle for the box is priceless.)

"Shaggy: Looks like it's just you and me now, Scoob."
 * In Where's My Mummy?, the gang sits in sad silence over Velma being (presumably) turned to stone. Scooby mournfully wails for her.
 * In Music Of The Vampire, Shaggy thinks he's been bitten by a vampire (he was actually grazed by an errant stake) and seeks refuge in the swamp. He tells Scooby to let him go it alone for fear of turning into a vampire, and this potential split up is heart-tugging. Shaggy can't do it, as he and Scooby suddenly reunite.
 * In the Live Action movie, the entire gang splits after Velma quits, leaving only Shaggy and Scooby. Shaggy drives the Mystery Machine away while Scooby looks out the back window for the others, heartbroken.