Shimano XTR CN-M980 10 Speed Chain
This 10-speed chain is an industry-first mountain-bike-specific chain, specifically optimized for 10-speed Dyna-Sys drive trains with mud-shedding, task-specific link plates.
This chain is lightweight and expensive. But I've broken at least 3 in the past year. Make sure you have a quick link when using this chain so you won't get stuck out in the woods. If you're cranking hard, I think the hollow pins just don't last that long. I'd recommend the XT if you want more reliability. Get the XTR if you want to save a little weight and add some bling.
I take good care of my drivetrain. It gets cleaned often and the chain gets white lightning about every 5 hours of use. This chain replaced an XT chain that was just worn. After about 150 miles of use, some links bind. None of the links where a master pin is inserted bind. The only fix is pulling out a pin and replacing it. It is a bad feeling to have a couple of links seize up when hammering up a hill. Skip, pop, bang. It doesn't shift as well as other chains I've used too. Bummer, normally Shimano stuff rocks.