There are several variables that will determine what is best for you: If you are street riding or racing, your rim size, and tire width.
For street riding with no tire clearance issues, an "o" ring or "x" ring chain will give you the longest chain life.
For racing people typically use a non "o" ring chain, for its thinner width and light weight. Chaparral have the D.I.D. 520 ERT on sale right now (which is the same chain as I have on my 426) for $50, this is a great deal-retail is over $80. chaparralmotorsports.com