Stan and Francine's headstones at the end of the episode say they died the same year, but were born four years apart. This goes against previous information that said Francine is only 10 months younger than Stan.
The "Japanese Funk" that Stan plays in his car stereo is "Monochrome Effect" by the Japanese band Perfume.
Steve's friend Toshi always speaks in Japanese and never in English, but when Barry wants to play "Hide and go Pee", Steve, Snot, and Toshi's animations clearly show them all yelling "Barry, no!" This also happens during the discovery of the sex doll, then the four of them, Toshi included, shouts "A shot for shot remake of the movie Mannequin!"
Roger's opening credits disguise: the outfit he wore as a fake hostage in the episode "Frannie 911"
The episode title, "May the Best Stan Win", is an obvious allusion to the term "may the best MAN win," commonly used to express superiority before a competition.
Terminator 2: Two References
First, when cyborg Stan first appeared, leaving a trail of fire behind him, and again when he sank into the hot chocolate while holding up his thumb, as the Terminator did at the end of Terminator 2: Judgment Day.
When Stan's Cyborg knocks Stan into another boat in the Tunnel of Love, Stan knocks a child into the chocolate river. The mother then yells "Augustus no!". This is a reference to the book Charlie and The Chocolate Factory by Roald Dahl (later made into a film called "Willy Wonka and The Chocolate Factory" by Mel Stuart and into another one with the original name by Tim Burton) in which a child, Augustus Gloop, falls into a chocolate river within the factory.
The Benny Hill Show
The music and the manner Barry runs through various doors as he tries to find the bathroom is an allusion to the British slapstick comedy.