So, suppose Nintendo...

[bluaki]

They'd also have to have an arcade filled with things gamers from any region couldn't get their hands on. How about showcasing the arcade mario karts, or, I don't know, Earthbound.

This would be the best suggestion so far. An arcade that is actually filled with fun games. Well, of course they'd have the typical things like a claw machine for cute Nintendo character plushes and stuff like that.
An arcade version of Smash Bros. also seems like it'd work. Just leave the game settings at an unchangeable number of minutes time or stock lives, remove single-player and miscellaneous menu items, and make things like unlockable characters available.

MARIO KART GO-KARTING

ITS A ME MARIO SO LETS A GO, BITCH

Just don't "accidentally" drop the peel of a banana you were just eating on the track and get kicked out of the park.
Oh, and watch out for blue shells.

STAR FOX SHOOTAN GAME?
AND YOU CAN BUY A STAR FOX HAT WITH FOX EARS ON IT AND THEN ALL THE WANNABE FURRIES WILL BE LIKE "LOL LOOK I'M FOX XD ^_^"
okay that might be dumb

Starfox could also have a flight simulator.

[jnfs2014]

Dang, man, you beat me to it. I had the same exact idea. :D

All the ideas here would be pretty awesome, but how about some.....rollercoasters (and other stuff). D:

Mario Series: A rollercoaster galaxy where you see all of the characters while going through the level on a rollercoaster. Have a "Power Star" item in the gift shop with "Rollercoaster Galaxy" on it.

DK Series: GIANT BARRELS or MINE CART MADNESS

Zelda Series: Spirit Tracks would be pretty awesome.

Pokemon Series: (3D rollercoaster) You're in a cave, and you try to find pokemon while you're on a mine cart that's going fast across the cave. Pokemon such as Zubat fly over you and Geodude try to use a Rock attack, to which you'd "luckily" evade it, like the Saw rollercoaster that's out. Also Pokemon Snap with better visuals (maybe put it as a 3D show).

Kirby: Kids rollercoaster that involves the Dragoon. Maybe do some sharp turns and a few small ups and downs.

Star Fox: As already mentioned, flight simulator. (DO A BARREL ROLL!)

Metroid: This could be a shooter-type ride, where you'd be assisting Samus.

History of Nintendo attraction definitely.

And what mack said.

[JrDude]

I thought of this in the past, it would be AWESOME!
There could be an archery area next to the Zelda ride where people get to shoot with bows that have no sharp part or something.
There are a lot of things you could do with Pokémon, though those ideas sound cool, they seem unlikely (but who cares? none of this is gonna ever be anyway!).
There could be a roller coaster for Mario Galaxy, you rocket through space and see mostly stars, sometimes it slows and you see some cool Mario Galaxy planets with some characters on it, then it makes that star flinging sound and you zoom through more space.
Star Tours Star Fox style? Possibly with R.O.B. as the pilot?