If you've little to no intention of getting Resident Evil 6, or plan on picking it up when it goes on discount sometime in the future, but have a yearning to see what the fuss is all about, then there's a good chance you'll want to watch the following video.
The video comprises over three hours of in-game movie footage that to make up the story of the entire game minus the combat/action/interactive bits. It contains every single cutscene from the game, from all four of the game's main campaigns, with Leon, Chris, Jake, and Ada.
We don't recommend watching it unless you're absolutely certain you have no intention of buying or playing the game for yourself, because it's the very definition of what a spoiler is.
That said, it's not surprising how Capcom put in the length of two movies into the game given how they intend to redirect the series in a more cinematic direction.