If I have to go out and buy a plug, I’ll get an NGK as a first choice. With that said, the 2 stroke Lawn Boys I’ve gotten into take a hot stubby little plug-NGK BM4A or Champion CJ14. Most of the big box stores and local hardware stores carry the Champion on the shelf, while I generally have to order and wait for the NGK at the auto parts stores.
A couple came to me with the expensive E3 plugs installed. I’d personally have a hard time spending $8+ on a copper electrode plug, but I will say that I ran one in my main mower all year this year and it started on the first pull every time(once I learned it’s choke/primer secret language).