I prefer Super Mario, although that is mainly because I've only played two Zelda games period (a little bit of the old one on the SNES and BOTW for the Switch). I've had several yeaaaaars of playing Super Mario Games that the history and nostalgia the games give me put it above Zelda, even though BOTW was really enjoyable and got me more interested in the series. The likes of Super Mario Sunshine, Super Mario Galaxy, Mario Party, Mario Kart etc. have a special place in my heart.
Zelda is the way to go for me, because I was never good at platformers like Mario. It didn't help that my first Mario Game was Super Mario Sunshine .
Mario for the fact that I've been playing Mario for years and only two LoZ games (the NES and SNES ones). But maybe one day that'll change since I've always wanted to play more Zelda games...
Mario's just kind of silly to me. I like Zelda because of the fantasy setting, over Mario's.... uh.... mushroom setting.
I for one like Super Mario partly for its setting (although it's nowhere near Pokémon in that particular kind of love). But I have lot more fun experiences with games in that series than in Zelda. It's also more varied thanks to its great number of spinoffs, and I've played a ton of those (especially Mario Party). In comparison, I've barely played any of the Zeldas at all. I love the top-down ones playstyle-wise, but the only Zelda I've EVER beaten is Four Swords Adventures. I never got far in any other game, period. (Note to self: Play LttP myself at some point)
Both, easily. I do stink at platformers, but at the same time I love Mario's aesthetics, while though Zelda isn't all that difficult for me I do have a hard time enjoying some of the things about the games themselves. Both make for some nice theory fodder, though.
I've sank like 140+ hours into Breath of the Wild and I haven't even bought nor had the desire to buy Super Mario Odyssey yet. :\ It's really telling to me as to where my interest lies with the Mario series as of late. I suppose in short... I like the story of Zelda a lot more than I do with Mario. It's so weird because I've practically grew up on Mario games, but I think during my childhood I missed out on things like Super Mario Sunshine (played a bit of it but never finished) and I missed out on Super Mario Galaxy... the more things that I missed out on, the more I start to lose interest. ... Then again, before BotW, I haven't played a Zelda game ever since Wind Waker, so maybe all I need is to force myself to get into Mario again, after all.
I like "The Legend of Zelda" more because it has more variety. A 2D Mario Jump 'n' Run could be funny for a few hours but after that I would find it boring (But they always have the best story.) . 3D Mario's could be better, but I never played one because I'm too poor for one. So yeah, I think Zelda is better.
Neither if I'm completely honest, but if I had to pick I think I'd lean towards Legend of Zelda, more of a lore behind it