Well, I think, that in the eyes of a casual gamer, PS2 has the best lineup. I mean with GTAVC and all...(even though I dont like GTA

)..I mean, I'm not saying its only casual gamers that will buy GTAVC...but you gotta admit, casual gamers will be like "Stealing cars and killing, w00t!!" or something like that so I would say that GTAVC is a killer game...and also, because I am a hardcore RPG gamer, I love PS2's fall line up, it has so many good RPGs that you people just seem to ignore, like, besides KH, there are just as good RPGs like: Grandia Xtreme, Legaia 2, Suikoden III, RPG Maker 2...just to name a couple, I never see anyone here even care about those games...meh.
Anyway, as for GCN, in terms of the games that I want to buy, it has the most diversity, besides RPGs, theres nothing else on PS2 that I would buy besides them RPGs...yeah...games like DMC2 and Sly Cooper can all be beaten if I rent them

. But for GCN there are games like MP, SFA, AC, PSO...all games that I want to get this fall...plus theres NHl 2K3 but thats also on PS2 so I can't compare.
Games That I want:
GCN: Metroid Prime, Animal Crossing, PSO, Star Fox Adventures, NHL 2K3 (ok so I cant really compare cuz its on other consoles, but I dont care

)
PS2: Legaia 2, KH, Suikoden III
See what I Mean By Diversity? all I want for PS2 is rpgs...
But, its time to make a fair judgement:
GCN: MP, AC, SFA, PSO, Bond Nightfire, and I know there are a few more, but I cant really remember them.

PS2: KH, Suikoden III, Legaia 2, GTAVC, Sly Cooper, Ratchet And Clank..hmm...what else is there besides Sports games....uh..anywho...
I guess really, there is no true "best fall line up" ...it all depends on what games YOU want to get, so I'd say arguing about it is stupid and pointless, but you can go ahead.

I only want 7 games this year...3 PS2...3 GCN ..+ NHl 2K3 but thats on all consoles...so....
I'd say its a tossup between PS2 and GCN, really....Xbox has...like..what...Shenmue 2 and Splinter Cell? ...but then again Splinter Cell is multi platform..oooh and theres Panzer Dragoon too...
Yeah, so in conclusion: it's the buyer's opinion, its what games you want.