“Magic Bullet, as has been mentioned, comes with a preset Look for Bleach Bypass.  It works pretty well, and is a little more sophisticated than what simple duped layers and transfer modes will get you.  It was meticulously matched to a DVD of Saving Private Ryan, and is very adjustable. 

BUT, having said that, I'd like to throw out a fun recipe for a cheap & easy BB look that's free.  Why would I do such a thing?  Well, we'd hardly expect you to buy Magic Bullet Suite just for the Bleach Bypass look.  And I'd rather encourage the cool homebrew tinkering discourse on this list, rather than suggest that plug-ins (even mine) are always the answer.  The fact is that you can do some amazing stuff with the built-in features of AE itself. And from a business side, I think people who experiment with and explore 
those options to the fullest are by far the more likely ones to recognize the hard work and careful attention that we put into Magic Bullet. 

OK, so here's the deal:  Do just what the Kodak page describes Bleach Bypass as -- a B&W image superimposed on a color one.  "Superimposed," in this case, meaning like would happen if you held two pieces of film together in the projector.  The transfer mode for this is Multiply. 

So Multiply one copy of your footage on top of the other.  Use Shift Channels to make the top (multiplied) one Luminance only (B&W). 

This should already look pretty good.  From there, I'd add an adjustment layer where I'd dial in the saturation and contrast. 

Hope that helps.  Like I say, Magic Bullet does this and more, but as has been pointed out, for a price.  Hope this gets some experimental juices flowing.”