This is like Proto red V's Best episodes per season and that's why I'm giving him credit. What you have to do is create a list of the season and your least favorite Spongebob episode in that season.
Example:
S1: I was a teenage Gary
S2: Dumped
S3: The sponge who could fly
S4: Good Neighbors
S5: Waiting
S6: Truth or Square
S7: One coarse meal (Least Favorite)
S8: Demolition Doofus
S9: Squid Baby
Example:
S1: I was a teenage Gary
S2: Dumped
S3: The sponge who could fly
S4: Good Neighbors
S5: Waiting
S6: Truth or Square
S7: One coarse meal (Least Favorite)
S8: Demolition Doofus
S9: Squid Baby