Since the decline of Sonic, i would think Pokemon came in second, as far as gamers knowing about it goes.

I'm guessing there might be a Wii gamer who uses the console mainly for Wii Fit/Wii Sports that may not know about Mario.

Maybe there are some Nintendo DS owners as well who only play Nintendogs or something.

Or that Horses game.

Mario is as well known as any other international cultural icon. Doesn't mean there aren't people that don't know him (hell, there are still uncontacted tribes in the world!), but yeah, just about anyone in most countries will know Mario.

Not nearly as many people would know sonic, and as for that Final Fantasy guy. Don't most final fantasy games have different characters? Perhaps I'm wrong on this, but wouldn't this guy only be in one main FF game and some spin offs? I'd say that unless you've played a game with him or frequent game forums, you probably have no idea who that guy (girl?) is.

I never met the guy.

Mario - YES
Sonic - yes
The other guy - Who is?

I dunno..Thre is so mant Sephiroths avatars and Sephiroth5187597 on this site and other sites so I thought it would be popular.Also almost all my friends knows Sephiroth.
But yea Pac Man is also very well known.

31 years playing games, no idea who Sephiroth is.

There's a higher chance people would know who Kefka is than Sephiroth?

Ok, is Sephiroth the spiky haired dude from Final Fantasy? If so. Any non gamer shown that picture will have no idea. And a lot of gamers will respond. "some spiky hair japan style game guy".