Chris and Piers' become ten times funnier when you notice that they look absolutely freaking serious when playing on the playground equipment.
If facing two J'avo as Ada at the playground, one of them will... jump on the other's shoulder.
When Sherry and Jake reunite in a locker room after being captured by Neo Umbrella, Jake immediately looks away from Sherry in embarrassment because she's wearing a fairly revealing patient's outfit. Sherry looks down at herself and quickly ducks behind a locker door. A little bit later, when Sherry is changing in front of Jake (they're pressed for time and not exactly spoiled for choice of changing rooms) and facing away. Jake takes a long look at her back, then turns away to find some clothes, all without changing his expression or acting as if anything actually happened.
Jake and Sherry jump into a metal bin to hide from Ustanak. Whispered bickering ensues about who’s touching whom.
Sherry: “Keep your hands to yourself!”
Jake: “Hey, you’re the one rubbing up on me. Besides, what makes you think you’re my type?”
Sherry: “I would shoot you if I didn’t need you alive.”
Yet another one from the Jake campaign: "You jarheads all look the same to me, sorry." This, coming from an Action Genre Hero Guy, when said to Chris and Piers, who both have full heads of curly hair.
In Leon's story, the Rasklapanje's hand can be shot off and attacked. If the attack button is pressed near a microwave, instead of throwing the hand away, Leon will shove it in the microwave, and we get to hear the sound of the hand blowing up. In Chris and Piers' campaign, you can shove it down a toilet. In Ada's campaign on the Carrier, you can throw it into a pot of boiling water in the kitchen.
The cutscene before the Ustanak fight at the plane crash site:
Jake: "Him again?"
Leon: "Friend of yours?"
Jake: "More like an ex-girlfriend. Guy doesn't know when to quit."
The final fight sequence in Jake and Sherry's campaign is possibly this game's equivalent of Chris punching a boulder, which means it's pretty damn hilarious. Still doubles as a Crowning Moment of Awesome, though.
In one chapter in the Sherry/Jake storyline, there's a section where one plays a piano to get a medallion. Jake plays Chopin's "Revolutionary Etude", Sherry plays "Twinkle Twinkle, Little Star".
Leon just before he and Helena fight the infected Simmons for the second time. Possibly funnier if you are a fan of Quantum Leap.
(The duo watch as Simmons turns into a giant monster)