Recently, I've rewatched the entire series from seasons 1-9. I'm currently watching 10, but I don't think any episodes in there will make either top 10 list, so I'll go ahead and make this now.
It was incredibly hard to select the episodes for this list considering that a vast amount of comic gems came from SpongeBob SquarePants, particularly the first three seasons. Therefore, here is a list of episodes that were unfortunate snubs from this list, but are still extremely good episodes, listed in production order.
And now, on with the main list.
This episode is quite different from the norm. Instead of following SpongeBob's exploits around Bikini Bottom, which typically involve his job at the Krusty Krab, the episode takes more of a meta approach to the typical plot by serving as a training video for new employees (evident through the title).
The jokes in this episode are brilliant, particularly the "Hoopla" fish and the graph/giraffe bit. The funniest part, however, is the ending; the episode builds up to revealing how to make a Krabby Patty (the process of which has been notoriously omitted from the entire series). Right as the narrator is about to reveal the secret, the episode ends.
This episode's premise revolves around a Krusty Krab commercial. Despite the commercial airing at 3:28 am and SpongeBob having a very limited role in it, the "fame" eventually gets to his head. The episode serves as a fantastic parody of Hollywood stars, likely influenced by the writers' experiences with such.
The buildup of SpongeBob's "fame" is fantastic. Towards the start of the episode, a old man appears to recognize SpongeBob from the commercial, although it is revealed that he is confusing SpongeBob with a cereal box. Later on, SpongeBob overhears two customers discussing a TV star's singing act, and he believes that they are referring to him, inspiring SpongeBob to launch a singing career with one of the most brilliant moments in the show's history.
SpongeBob's blindness to what the customers at the Krusty Krab actually want (spoiler: food) is the funniest part. He only realizes this at the end, when he discovers his "new" career by accidentally knocking patties onto the grill; later, he remarks, "I can't believe I gave up fry cooking for this!"
In this episode, Plankton, the primarily villain of the show, is miserable after failing to steal the Krabby Patty formula once again and realizing how good Mr. Krabs (the owner of the Krusty Krab, and SpongeBob's boss) has it compared to him. As a result, he uses one of his devices to switch lives with Mr. Krabs.
Most of the humor in this episode is provided by Plankton's adjustment to his new life. Particularly, he must deal with SpongeBob's annoying antics, which infuriate Squidward, SpongeBob's neighbor and coworker. Plankton attempts to remedy the situation, resulting in a hilarious chain of events that include Squidward's terrible fry cooking skills and Krabs' daughter Pearl arriving at the Krusty Krab.
Things go wrong when Krabs, who is now living Plankton's life, arrives at the Krusty Krab to steal the formula. A hilarious battle scene ensues, highlighted by Krabs' state of nudity. At the end, Plankton realizes he is content with his own life and returns home. The episode is hilarious overall and as it is the first episode in season 3 by production order, an excellent start to the season.
7: Wet Painters
In this episode, Mr. Krabs hires SpongeBob and his best friend, Patrick, to paint his house instead of destroying the Krusty Krab through their "games". This episode is hilarious because Mr. Krabs' walls are covered with priceless artifacts that SpongeBob and Patrick cannot get paint on. This scene perfectly explains their situation and also provides one of Patrick's brilliant but idiotic moments.
The bubble eventually pops and covers the wall with paint, but it misses all of the artifacts. All seems well until they notice that they have gotten paint on Mr. Krab's first dollar. The second half of the episode chronicles their attempts to remove the paint (and includes another brilliant Patrick scene, one of my favorites from the entire series). Eventually, Mr. Krabs returns and tells them he was messing with them and that the paint comes off with saliva.
One of the most universally famous SpongeBob episodes for its various lines and scenes, particularly the CHOOOOCOLATE!!! guy.
The episode is about SpongeBob and Patrick's quest to become entrepreneurs and sell chocolate bars door-to-door. Their ventures are not quite successful, as their field of potential customers include the aforementioned CHOOOOOCOLATE!! guy, an "injured" man, this guy, an old lady and her even-older mother, and more. The episode's humor is primarily from SpongeBob and Patrick's terrible entrepreneurship as well as the plot twist at the end (watch the episode to find out!).
5: Sailor Mouth
In this episode, SpongeBob and Patrick learn what curse words are after SpongeBob finds one written on a dumpster. As it is primarily a kids show, the words are obviously censored, but the hilarious part is that instead of traditional beeps, they are censored with dolphin noises. As a child, I thought it was hilarious, and now that I actually know curse words, it's even funnier because you can imagine what the characters are saying in their censored exchanges.
Mr. Krabs finds out and tells SpongeBob and Patrick not to say the word anymore. They comply until SpongeBob loses at a board game, resulting in a very hilarious closing sequence where Mr. Krabs is disappointed and takes the two to paint his mother's house as punishment. However, after stepping on a rock, he says the bad words himself, leading to himself getting punished by his mother. The episode is fantastic for all ages, with the "adult" humor for older viewers and the lesson that using profanity results in consequences for the younger viewers.
This episode has perhaps one of the most unique plots in any SpongeBob episode to date. While SpongeBob's squirrel friend, Sandy, is hibernating for the winter, he and Patrick sneak into her underwater treedome but are trapped after the lock freezes. The two accidentally wake up Sandy while pretending to be Texas outlaws and are beaten senseless.
After Sandy goes back to sleep, SpongeBob and Patrick are left in the frozen wasteland without any additional clothing. All they can find is Sandy's fur, which they rip off to have warmth for themselves. The episode ends abruptly when the winter ends and all the snow melts, resulting in Sandy discovering what the two have done.
3: Idiot Box
In this episode, SpongeBob and Patrick order a giant TV just to play in the box, much to Squidward's annoyance. SpongeBob and Patrick use their "imagination" to create realistic-sounding scenarios just from the box, such as Mountain Climbing Adventure (part 1 and part 2), this "cop chase", a realistic space launch, and Robot Pirate Island.
Squidward attempts to figure out how they make those noises, trying to get in a box himself. He tries to forget about it by watching TV, but everything on is about boxes. When SpongeBob and Patrick go to sleep, Squidward goes into the box and realizes he has made it work for his imagination, but in reality, a garbage truck has picked it up.
Additionally, a channel called Hollow Hills Productions made a live action cover of this episode, which is completely hilarious.
2: Band Geeks
This ranks highly among the vast majority of SpongeBob fans' top ten lists, and deservedly so.
The episode's premise is centered around Squidward's attempt to put together a band in four days to upstage his high school rival, Squilliam Fancyson. The preparation phase goes terribly for him, but fortunately for the viewers, it leaves behind several comedic gems. These include this BRILLIANT one-liner from Plankton, Patrick's kicking, Mr. Krabs, BIG, MEATY, CLAWS, and one of the saddest anime deaths of all time (this scene would've been cut for sure if it aired after 9/11, rather than a few days before).
At the end of the fourth day, Squidward is thoroughly disappointed in the group and goes home dismayed. However, SpongeBob rallies the group together and delivers an incredible performance, amazing for the laughs as well as due to the fact that Squidward rarely comes out on top on this show.
And finally, here we are at my favorite episode. There are so many good things to say about this that it is hard to choose just a few to put into this list. This episode's plot centers around SpongeBob and Patrick "camping" just outside their houses. Squidward later joins them and tries to teach the two about proper camping. This fails miserably, but the hilarious part is that SpongeBob and Patrick take his efforts seriously, as seen in this scene.
After Squidward becomes acquainted at the campsite, they sing the Campire Song Song. Now, I am traditionally against including any sort of songs in animated TV, but this episode does it perfectly (as do some others on this list), with the hilarious sequence of Patrick attempting to sing along and Squidward's refusal to.
Later, SpongeBob and Patrick bring up the topic of "sea bears", which they have seen in tabloid magazines. Squidward adamantly denies their existence and attempts to lure one to the campsite. To his dismay, they really do exist; one appears and quickly proceeds to maul Squidward in one of the show's most hilarious sequences. SpongeBob and Patrick save Squidward and dispatch the sea bear. Overall, the episode is extremely unique in terms of its plot as well as humor, definitely standing out even among other extraordinary episodes.
Additionally, Hollow Hills Productions also made a live action cover of this episode as well.