The Zero said:
I'd stick with the Gamecube, but then I'm completely biased. Some must play GC games are;
Super Smash Bros. Melee
Eternal Darkness
Metroid Prime*
Paper Mario: The Thousand Year Door
The Legend Of Zelda: The Wind Waker
F Zero GX
Resident Evil 4*
Pikmin 2*
Super Monkey Ball
* Also available on current gen consoles.
This is an okay start. Psyhonauts, Chibi-Robo, Prince of Persia Sands of Time Trilogy, Beyond Good and Evil*, Viewtiful Joe, Metroid Prime 2*, Pikmin 1*, Animal Crossing, Soul Caliber 2, Skies of Arcadia: Legends, Sonic Adventure 2, Super Mario Sunshine, The Legend of Zelda Collector's Edition, The Legend of Zelda Ocarina of Time Master Quest, The Legend of Zelda Twilight Princess*, Metal Gear Solid Twin Snakes, Mega Man X Collection, Mega Man Anniversary Collection, Fire Emblem: Path of Radiance and just so much more.
Not: All of these are playable on Wii. If you want a next-gen console still and decided you wanted to stick with Nintendo, you'd have all of these games as playable, plus the Wii exclusives. And I mean the good ones, like The Last Story (fingers crossed...), not Wii Sports.