1. OEM is usually a quality plug on quality engines. I dump the chinesium plugs from my small engines early. So, it depends on brand/pn that OEM installed.
2. Champion hasn't wronged me yet.
3. NGK hasn't wronged me yet.
4. Toss in Denso/Bosch/Autolite......
What I like doing is varying the plug picked so that I can see if there is any running issues, or plug longevity issues. I just haven't found a non-knockoff that gives me problems. I do find that some geewhiz plugs do little. I've had engines run 4-6 different plugs. Also have a car with 4 different brands of brake rotors.