Resident Evil 2 has a moment where Leon catches up to Femme FataleAdaWong, and attempts to make conversation. Keep in mind Leon is wearing a blue police uniform with insignia everywhere and the giant letters R.P.D. emblazoned on his back.
Leon: "Ada, I don't think I've introduced myself yet. My name's Leon; I'm with the RPD."
Ada: *shrugs as if to say "You thought you needed to tell me this?"*
Another funny moment is in the N64 version of the game. Rebecca has a report about Billy Coen being dead, but she mispells his name 'Koen.'
In the ending of Claire B, Birkin, now a hideous Blob Monster, bursts into the train carriage with Leon. Leon's response?
That's what I call ugly.
Also in Claire B, Claire tricking Mr. X into the smelting pool by throwing Sherry's pendant (which Mr. X had been after all along, as it contains a G-virus sample) into it.
The Tofu Survivor, an extra minigame featuring... Tofu, a human-shaped block of tofu that has the same animations as the playable characters. But he makes a silly noise whenever he takes a step. It even echoes in certain rooms, like the police station main hall. He turns more and more red when he takes damage and speaks Japanese in a high-pitched voice when he's attacked.
The sheer weirdness of Chief Irons, at times;
Irons: And to think taxidermy used to be my hobby.
Ada, WAIT! ADA! WAIT!!
The whole entire exchange with Claire Redfield and Robert Kendo is hilarious. The way he calls her "babe" and other sexual innuendos is kind of funny because it sounds like the audio has been horribly redubbed compared to the Leon version of the dialogue.