It's a forum game but...

[Lario]

... we come up with the ultimate "video but x happens" title. It's like the sentence finishers thread but it is a title that never ends.

I'll start:
Moskau but every "Moskau" is replaced with...

 

[Magikrazy]

...footage of a legend of zelda playthrough but every time link enters a dungeon it cuts to...

 

[DragonFreak]

Every let's play of a zelda game, but every time link opens a chest...

 

[Kerrigan]

...It cuts to a Metroid LP but every time Samus shoots her gun...

 

[Weasel]

The Nutshack theme plays but every nutshack is replaced with...

 

[Kerrigan]

...The whole Hunger Games trilogy but every word is replaced with...

 

[Magikrazy]

...the DK Rap but the phrase "coconut gun" is replaced with...

 

[Kerrigan]

..."Watch for Rolling Rocks - 0.5 A Presses (Commentated)" but every Mario sound is replaced with...

 

[LN1]

...HP but every time Mario gets hurt...

 

[TPG]

...Every LazyTown episode plays but every time Robbie Rotten appears...

 

[Lord Bowser]

the opening scene from hotel mario plays but every time mario blinks...

 

[Magikrazy]

...every smiley on super mario boards appears on screen for exactly one frame but is replaced with...

 

[Kerrigan]

...every episode of Law & Order but every "Bong-bong" sound is replaced with...

 

[DragonFreak]

...majora's mask's dawn of the final day screen for 24 hours but after each hour...

 

[Lord Bowser]

...a longplay of super paper mario comes up but every time tippi speaks...

 

[DragonFreak]

...a compilation video of every line of Starlow, but every other frame of Starlow that you know DragonFreak would want to punch her face is replaced by...

 

[Magikrazy]

...a random episode of any nickcom produced by schneider's bakery, but every time a laugh track is used it cuts to...

 

[Lord Bowser]

...a live read of dragon problem, but every time the word "jerkwad" is said...

 

[LeftyGreenMario]

...an LP of us playing Mario Party 6 plays, but every time Wario loses...

 

[DragonFreak]

...is replaced with a video of WAHales only played backwards, but every time "yenom" is said...

 

[Lord Bowser]

...the entire zelda cartoon series plays, but every time link says "well excuuuuuuse me, princess"...

 

[Kerrigan]

...all three Mario cartoon series (Super Show, SMB3, and another one I don't remember) play but every time Luigi talks...

 

[LN1]

...an entire Metroid Prime Longplay is played but every time Samus fires...

 

[DragonFreak]

...it's replaced by the song Regretoid by Starbomb, but every time there's a rhyme...

 

[Lord Bowser]

...the entire avgn playlist is played, but every time avgn says "fuck"...