The best replacement for spark plug is non resistor.

The best alternatives to spark plug are rated as following:
★★★★★  non resistor
★★★  cold spark plug
★★★  coil pack
★★  coil bad
★★  platinum spark plug
★★  iridium
★★  battery
★  iridium spark plug
★  glow plug
★  ignition coil
★  fuel injector
  copper

Your alternative for spark plug is not listed? Suggest!
Speaking about spark plug, one probably shouldn't forget about compression release.

Other search terms related to spark plug and their ratings are:
★★★★★ compression release
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spark plug
non resistor
cold spark plug