What about Geist, Eternal Darkness, F-Zero, Golden Sun, Kid Icarus, Mother, Advance Wars, Star Fox. They are all hardcore franchises, and there's a lot more.

I will have to go with TLoZ as the most hardcore one.

I've played SRPGs before, so if Fire Emblem is supposed to be one of the hardest series of those, I would say it's likely Nintendo's most hardcore series.

 Yeah, Kid Icarus was pretty hard when I played it last year, even though the game was decades old.

I trully hope Nintendo decides to make the next Kid Icarus game more like Metroid. Not in gameplay aspects, but in terms of 'hardcoreness'. If Factor 5 is really making it, then I've not much to worry about.

Indeed, Fire Emblem even made me grumble on Easy mode. But it's such an rewarding game... so many good times with Ilyana and Jill. ^___^

Erm... list! Yeah!

1. Fire Emblem
2. Metroid
3. Smash Bros.
4. F-Zero
5. Pokemon

F-Zero, Super Smash Bros

Fire Emblem is probably one of the most hardcore franchises in the entire industry let alone Nintendo.

Fire Emblem
F-Zero

Fire Emblem, Adavnce War, Metroid, F-Zero, The Legend of Zelda.

1. F- Zero *GX*
2. Fire Emblem *Radiant Dawn*
no other nintendo games that I played come remotely close to as hard as these games
3. Metroid
4. Advance Wars
5. Star Fox

Elite beat agents, just ignore the "Touch Generation" logo on the box, it's really hardcore