Super ultra 16x uranium-plutonium quintuple fire plugs are great- if the engine was designed for them.
I've been tempted by all the promises before, too, but I've learned that spark plugs are one place to not try to upgrade. Engines that come from the factory with nothing special copper plugs like having nothing special copper plugs in them. Parts counter dudes (been there, too) will try to sell whatever their computer tells them will work with your engine, but stick with the stuff that came in the engine from the factory.