Shimano Dura-Ace 7901 10 Speed Chain
The new asymmetric design of the Dura-Ace Redesigned plates that improve the contact interface with the cogs. Other improvements to the links provide greater durability and life with less noise and smoother function.
So aside from the goop that Shimano puts on all of their chains, this directional chain is absolutely awesome. Pair this with a cheap shifter/derailleur set and a new set of cables and you will be impressed.