Mario is more popular than Zelda. This is a FACT. Mario is the mascot of Nintendo and there are more mario games than zelda games. I think it mainly happens because not only is Mario older but it is also the platform. Nintendo uses a technique for the Mario games they use for decades now and it still works. Somehow to the audience Mario never gets boring. I still prefer the Zelda games because to me it has more depth in the story. But Mario is a very close secondI wouldn't say Mario is more popular. Among gamers who've played both, most would choose Zelda over Mario. From a view point of people who haven't played either, Mario might seem more appealing, as it is a broader franchise with more diverse games (sports, RPG, platform, ect.).