I've been rewatching SpongeBob on DVD lately and in general that show has quite a few funny ending jokes. Some I haven't mentioned yet:
"Dumped": As SpongeBob and Gary reconcile and leave, Gary stands there in his underpants and says, "Gary?.... I thought what we had was SPECIAL!!!!!" (fade out) I don't know why this gets me to laugh. Maybe it's the fact that he's yelling this in his underwear, or that it abruptly fades out.
"Opposite Day": Squidward yells, "HAPPY OPPOSITE DAY!!!!" as he chases SpongeBob and Patrick with a bulldozer. His delivery is what makes it work.
"The Fry Cook Games": Patrick and SpongeBob leave the stadium in their underpants, friends again. Patrick remarks about his yellow underwear: "You know, these were white when I bought 'em." Eeeeeehehehewwwwww...
"Squid's Day Off": The visual of Squidward's face deflating. So silly looking, and I like how he remains smiling throughout.
"Krusty Krab Training Video": As already mentioned, the end to this is gold, especially since they built it up all throughout the episode. "The Krabby Patty Secret Recipe i-" (cuts off)
"Grandma's Kisses": SpongeBob hugs his grandma; we hear Squidward and the Krusty Krab customers from earlier laughing at them from outside. What makes it work is that Squidward starts off with a small chuckle and it builds to crowd laughter as everyone's revealed.
"Procrastination": Much like "Squid's Day Off", it ends with SpongeBob ripping in half like a piece of paper after being told all his hard work on the essay was for nothing, smile still on his face.
"I'm With Stupid": "Oh that's right, honey, we don't HAVE a son." "Oh yeah." (Patrick's "parents" walk off) One of the most surreal endings ever.
"Bubble Buddy": A bubble floats up to Squidward's face, and he says, "Uh... hi?"
"Karate Choppers": Sandy: "I love karate!"
SpongeBob: "I love kara-tay!"
Mr. Krabs: "I love money-ay!"
Squidward: "I hate all of you."
Good ol' Squidward.
"Doing Time": After about the fourth "it was only a dream" as Mrs. Puff is falling, she says, "Oh forget it!" Fade to black. I love how the story itself just says, "screw it."
"Squid on Strike": Mr. Krabs: "In order to pay off the damages on me restaurant, you two are gonna work for me FOREVER!"
SpongeBob: "Ya-hoo! The strike worked, Squidward! We've got our jobs back, forever!"
"Forever!" echoes in Squidward's mind; narrator says "One Eternity Later" and we cut to a skull and bones of Squidward and SpongeBob in the Krusty Krab. Besides the obvious LOL WUT joke that it's impossible to have a "later" when it comes to eternity, as it's never-ending, I find it amusing that SpongeBob, a sponge, has bones.
