The very best new main gear tires, by far, are Goodyear Flight Custom III tires... breathtakingly expensive at around $160 each. My RV-6 came with a set of these from the previous owner, but I finished wearing most the tread off one so I just installed a pair of cheap AirHawks.
Lots of folks here swear by Desser retreads, either the Elite or the Monster retreads get good reviews. I intend to send my Goodyear FC-III cores off to Desser to be retreaded as "Elites".
The Aero Classic "Retro" tires (OEM from Vans) with the diamond pattern where the sidewall meets the tread are actually pretty good tires too.