Well, I pick GCN, not just because of the Nintendo-Fanboy I am... but polls prove its the favorite.
Sure, most polls "Which is your favorite Next-Gen console?" would say PS2... but GameFAQ's recent poll "Which console had the best E3 lineup" said GCN did, so, despite what most people choose, there's proof that Nintendo makes the "best" games.
Metroid Prime i think, was one of the best games of 02', a Nintendo Exclusive...
And aside from GCN, Nintendo itself has been the most successful video game company, owning two of the highest-selling games ever... SMB3 and Pokemon Yellow, and then some. LoZ: OoT is usually on many lists of the Best Game Ever, one of the 3 or 4 10.0 games on GameSpot and such. And I'm confident Nintendo will keep this up.
So I guess... simplified, my answer's GCN.