Fan-made videos, like spies, are a dime a dozen. But it's not every day that you see a fan video of this quality: Law Abiding Engineer, created by YouTube user TrueOneMoreUser, is an amazing work. Originality isn't high on the menu here - it's basically the trailer for Law Abiding Citizen - but the overlay of the Team Fortress 2 pantheon is absolutely flawless. It also adds some extremely inappropriate hilarity to the whole thing, particularly near the beginning, which despite the grimness of the situation I can't watch without hearing "BONK!" in my head.
The only downside to the video is the fact that it doesn't actually feature the TF2 voices; a wildly fake French accent would have been delicious icing on the cake. On the other hand, hearing someone say "Spies are a dime a dozen" warms my sniper heart, so I guess we can call this one a wash.