Awesome Music: Mr. Robinson's performance at the end of "The Debt".
"She's a lady, a fine lady!"
"You gotta think big, think small!"
"Warrior, Be The Warrior!"
Dude, Not Funny: Played with. When Miss Simian drives over an unfinished bridge, Richard tries to cut a lighthearted Bond One-Liner and Gumball, Anais, and Darwin all chuckle along. Then Nicole reminds them that she might be seriously injured...which leads to Richard cutting another joke...and then Nicole telling them to stop again...and then another one.
Fanon: Many fan-artists depict Penny as a deer when not in her shell.
Ho Yay: In "Responsible", Darwin keeps Gumball from drowning by breathing into his mouth via kiss, similarly to the two love interests in Waterworld. Though, in Gumball's defense, he was visibly against it.
"The Third" was essentially a friendship-affair plot, complete with the two "getting back together." Just replace every mention of a game with...other things, complete with "It didn't mean anything!" and "He's playing video games with my best friend!"
Gumball has been told "Go to him" twice in reference to Darwin.
Darwin falls in love with Gumball when he wears a wedding dress in "The Dress". To the point where he is actually stalking him, collecting sweat and generally being a Stalker with a Crush. This culminates in Darwin confessing his love on a roller coaster. And this is without mentioning the whole "I want more kids!" sequence.
In "The Pressure", when Tobias and Banana Joe cut down the treehouse, Darwin and Gumball, with eyes closed, accidentally kiss each other, thinking they're kissing Penny and Masami. The kicker? They both liked it.
"The Prank" takes it up just as much as well, as Darwin calms Gumball's hyperventilating by patting his head, then uses his fins to rub around his head, then kisses him on the cheek.
During a chase scene in "The Wand", Richard casts a 'love spell' on Gumball and Darwin to try and slow them down. To make Richard believe that the wand actually works, romantic music plays in the background while Gumball wiggles his eyebrows at Darwin.