BR8EVX used to be my plug of choice. Unfortunately, NGK stopped making this plug, so I bought all of them I could find. I install a new plug for every race, as entries fees are way to high to end up performing poorly because of a fouled plug. Now that I am at the end of my supply, I will be switching to the BR8EIX.
As a note, I give my used plugs away to folks who foul their plugs while trail riding.
Rick