Champions for plug chops and NGK for everything else.
Champions are nickel plated and the coating burns off at a definite point on the side electrode so tuning your jetting is easy once you know how.
NGK's because they have the narrowest heat range numbering system and they just seem to have better quality control, I have never had a bad plug out of the box. Plus the center electrode well seems to be deeper and wider than the others (greater arc-over resistance) for the equivalent heat range.
“She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself.”
— Han Solo