I absolutely adore the Hash Slinging Slasher episode. My #1 favorite.
I also love the episode where SpongeBob gets Larry the snail as a pet. LOL.
On another message board I belong to, someone was complaining about how they'd never let their child watch that show because it referenced sexual things (SpongeBob is a sponge, Patrick is a "dirty star", etc.). Reeeeally. That's really reaching for things.