For the illiterate. The topic title states which console had the most games that led to franchises that still exist today. Yes Mario started on arcades, but the series had the most titles and became the most recognized video game character due to the many releases on the NES. The topic isn't asking where the series started out, it's asking where the series initially had the most releases and the reason why it exists today. Mario Bros also appeared on the NES as well(same year as the arcade version,) and most following titles, all the major releases that have followed have been called "Super Mario." It's only ever went back to "Mario" over "Super Mario" if it was a spinoff title.
If you're picking out my response of Mario, how about I nitpick about a game that you've stated. Because if you want to really get technical, the title itself is irrelevant. SaGa started out on the NES as Final Fantasy 2, to the point that Squaresoft renamed the first actual SaGa game Final Fantasy Legends for stupid Americans to buy into the popularity of the brand. Just like Vampire Killer and Haunted Castle are Castlevania games, just like Persona titles are SMT games, Final Fantasy 2 is a SaGa game. Another thing to point out, Mario Bros is nothing like the rest of the franchise, where there are a lot of core similarities with Final Fantasy 2 and the SaGa titles.