[Zayl1015]

The first question is regarding the three skits on AMV Hell 4 with the hide and seek song. On all three of them, someone was getting shot, and I was wondering is that a parody of something? If so, of what?

The second is regarding the skit with all the anime going through to the song 'Smack my ***** up' (Im not sure if theres any restrictions on swear words, but im not taking any chances). Anywho... Theres that one part where it's not a anime and shows a guy, like, talking to another guy and he suddenly slaps him. What was up with that?

[AMVP]

In the tv show The OC, there was this scene where the main character gets into a fight with this guy. So this guy starts wailing on the main character, is getting ready to kill him, when his sister comes in and shoots and kills him. When he gets shot, there's this long slow-mo scequence where the song from the AMVs is played.
That was the origen. Later, on SNL, there was a viral video short featuring Andy Samberg and Shai LaBuff, where several people walk into a room and get shot or else shoot somebody else multiple times (like with the second of the AMV Hell videos). And that's where the joke got its start.
As for the slapping scene, that was a rather imfamous clip from an E3 expo, I believe, and I can't quite remember what it was all about. But there you go.

[Inkwolf]

If you read the Inside Jokes thread, you'll find links to Youtube clips of both those scenes, as well as lots of info on other jokes/parodies you might have missed.