Assuming you mean 80mm... Best? You mean quietest? Most powerful? Best compromise? Best quality? The quietest would be a papst. The most powerful is the Delta EHE (80CFM), but you'll be deaf in a week. Best compromise, with excellent quality is the Mechatronics. Best quality would be the Papst or Sanyo-Denki, with the Mechatronics right behind, but at 1/3rd the price.
In that case you want the Delta EHE (80 CFM, 52dB). I was driven nuts by the 60mm Delta (38CFM, 46dB), and you're dealing with a fan that is four times louder (6dB). A friend of mine has a Delta SHE 80mm (68CFM, 48.5dB), and I can't stand the thing, so do this at your own risk. No one living in the same house will be happy with you....
The delta does push a lot of air, but as already said, the Mechatronics is a great display of power, quality and price!
the deltas are the fans to have for max airflow. I have a few FFB0812SHEs, but the FFB0812EHE is the mother of all 80mm fans EDIT: @ 12v anywayz