I'm not gonna lie
Mario on the NES I totally get as being hugely innovative and pioneering both the genre and to a lesser extent a lot of traditional 2D game design conventions, and I respect it for that.
Mario 64, same thing. I totally get it.
Mario Galaxy- not really super innovative, but very inventive in its own right and a bona fide return to form for the genre. Again, I get it.
But man Mario on the SNES I really don't see as anything more than just "more Mario" and I honestly think every single Genesis Sonic is a hell of a lot more advanced in numerous ways, with Sonic 3 & Knuckles in particular pushing more boundaries for what an ambitious, top of the line platformer could be better than Mario ever did in the 16 bit era.
I guess I'm biased? I mean shit, if we're directly comparing the two franchises and their influence it's pretty much fact that Mario destroys Sonic in every single generation other than the fourth, but I don't think a retrospective comparison between arguably the two most important franchises in gaming at that time is a worthless discussion to have, and I definitely feel Sonic did a lot more to innovate in an era where Mario more or less just iterated on what was already there.