If you want the longest life, most transfer power, and best sprocket life, get a Diamond chain. If you can find an older "XDL" one in a white box (I see them on eBay sometimes), so much the better: my last one went over 40,000 miles and the sprockets are still good.
If you can't find the "XDL" then get the Powersport, or the Harley-Davidson version (more $$, same chain). Lube every 500-1000 miles, keep it adjusted, wash it at the quarter car wash like you wanted it to shine, then ride about 5 miles to fling out the water, then lube and let cool. Do this regularly, and it will reward you!
The O-ring and X-ring chains out there have internal seals to lube the insides of the rollers, but this does NOTHING for the chain and sprocket contact, where most of the wear occurs. The O-rings chains are about 91-93% efficient at power transfer: the XDL/Powersport is 97% efficient, and tends to run much quieter.
My two cents...