"You?" Squared

Two characters, maybe friends, maybe not, are skulking separately through back streets, participating in a Bar Brawl or some other combat situation. They back into each other, whirl, point weapons at each other—then shout, simultaneously, "You!"

Anime and Manga

 * This happens repeatedly between Jin and Mugen in Samurai Champloo.

Film

 * "They're after me! They're after you?!"
 * Variation in The Lion King: Nala tries to hunt down Pumbaa, but Simba comes to rescue. They start a badass lion fight for some seconds, then Simba loses again and says "Nala!?".

Literature

 * The bar brawl version is known as the "Double Andrew" on the Discworld, and is worth quite a lot of points. Bar brawls in Ankh-Morpork have become somewhat formalized.

Live-Action TV
"Kirihiko/Nazca Dopant: You! Shotaro: YOU! Kirihiko: Let's take this outside!"
 * Buffy the Vampire Slayer demonstrates this (albeit silently) with Buffy and Riley in "Hush".
 * Something similar to this happens in the Doctor Who episode "Partners in Crime", in which the Doctor and Donna meet for a second time — except they do it in mime, through a window.
 * In Kamen Rider Double, Shotaro is having a friendly conversation with another patron at the barber shop. They keep just missing getting to see each other's faces for some time. When Shotaro realizes he's been chatting with The Dragon, we get the following as the poor owner can only look on in confusion:

Newspaper Comics

 * Parodied in Hsu and Chan. When the titular Tanaka brothers encounter their lifelong rivals, Akira Yamamoto and his father, each of them says "YOU!" at least once, prompting a passerby to say, "...Me?". Chan slaps him upside the head and shoos him away so the confrontation can begin in earnest.

Western Animation
""My pot! ...Your pot?!""
 * Humorous example in Family Guy, involving Brian, his estranged son, and a bag of pot.

"Cyborg and Beast Boy: *Screeching halt* "Who's chasing you?!?" Beast Boy: "Girls!" Cyborg: "Chefs!""
 * From Teen Titans: Trouble in Tokyo: