Not sure you would classify them as the "best" available but, from a value for money perspective, I can vouch for the 808 #16 (V2) camera. I bought a couple in September and have pretty much used them constantly on my commute since then. I have one helmet mounted and the other rear facing on my mudguard. The battery life isn't great, but I have since got an external battery pack which more than covers it. So, for less than $100 all up, I've got coverage front and back. I've also noticed a "wide angle" version of the same camera - so that will probably be my next purchase.
I'm currently putting together a montage of "close calls" (and trust me there's been a few) with cars, cyclists, pedestrians and magpies which I hope to post to youtube soon. Will post the link here once it's up.