A quiz is the most fun way to find out. Make one in seconds, send the link, and let the bragging rights begin.
Under the heading Who knows the most? on the front page: making a quiz and sending its link to see who knows most. "Let the bragging rights begin" is playful: the fight for the honour of winning starts, so use the language's own idiom for it
Quiz to najfajniejszy sposób, żeby się przekonać. Zrób go w kilka sekund, wyślij link i niech wygra najlepszy!