I wonder if this is a continental thing? I grew up in Europe and everybody always pronounced SNES as "snes", then recently visiting America and chatting to a bunch of geeks, I was surprised that they all called it the "ess enn ee ess"
I rarely have an excuse to say it out loud, but my default would be 'Super Nintendo'. Not sure if that's standard here (Australia), but it's what I remember hearing as a kid.
I remember the same growing up in Australia, though nowadays I tend to say “snes” for some reason
Germany here. "Super Nintendo" or "ess enn eh ess". Precursor was the "enn eh ess" (eh as in less, not as in tea)