Hey GameCube fans: Got a free hour? If so, go read Emily Rogers' massive history of the Nintendo GameCube over at Dromble.
I honestly think Nintendo could have gained parity with Sony and Microsoft that generation if they'd gone with a DVD format instead of being so paranoid about piracy that they went with a proprietary mini-DVD-type disc (which probably did little to stop modders anyway).
A little more 3rd-party support would have helped as well. I still have my GC as a backup in case my original Wii dies, along with 2 Wavebird controllers and a big ol' stack of games.