Wii games (sport/fit/play), 2D mario platformers and Pokemon handheld RPG's are the big 3 everthing else pales in comparison.

Lol, I forgot mentioning Animal Crossing. Wild world was a beast in sales.

And I get that many means that Metroid is a part of the hardcore 3, but at the same time, I think there are just as many hardcore nintendo fans playing pokemon.

Metroid is considered the third in the big 3 because it is the third biggest unique IP. Mariokart is a spinoff from Mario which is a spinoff from DK. They are all the same universe. Smash Bros is an IP mash up. Mario (present day fantasy), Zelda (ancient fantasy) and Metroid (future sci fi fantasy) represent the 3 biggest unique characters and game worlds in the world of Nintendo.

Mario,Pokemon and Zelda are considered the big 3 im most people's minds even though they have a few other series that outsell them.

Sales wise i think it would go

Pokemon,Mario Kart and Mario (main series)

These 3 series sell the most and are the biggest console sellers most the time. Metroid is a good series but its nowhere near Nintendo's top franchises. Its more in the Fire Emblem,Pikmin and Kirby area IMO.

It's really Mario Kart, Smash, and Pokemon that are the big sellers.

i think it has to be pokemon... pikachu's face (or other pokemon) is just all over the place..... man they really need a new IP.... nintendo make the best characters....

I didn't think they made Pokemon? Aren't they just third-party exclusives?

Game Freak is 2nd party and Nintendo owns the IP.

Metroid is loved by many fans, but not so much by Nintendo.. And the rest of Japan.

While Metroid did get universall acclaim and some good sales in it's GCN days i'm sure it's at the bottom of Nintendo's "our most important games" list along with F-Zero and Star Fox. Real shame but the games never sold well.

I think Nintendo's true big three are Mario, Pokemon and Zelda.

I like TheLastStarfighter's explanation but I'm not sure I believe it 100%.

Metroid certainly has an avid following, but then so does Starfox, Pikmin, and Fire Emblem and the first two at least sell similar numbers to Metroid. I guess it's that Metroid pre-dated all those franchises (and Animal Crossing, Wii, Nintendogs, and everything else that vastly outsells it). Doesn't pre-date Kirby though and Kirby also sells similar numbers and is also a completely unique universe. But for some reason Nintendo fans tend to think Kirby sucks.