Different shells are a neat idea, until you look at the price tag on each one.
Games like Zelda: Four Swords and FF:Crystal Chronicles shoved connectivity down my throat. As well, WW gameplay expanded with a connected GBA, Animal Crossing exploited the "E-card reader", Splinter Cell even had extra weapons or levels when connected to the GBA version.
These are but a few of the examples I readily recall.
If you only spent money on the GC console and memory cards/controllers for it, you were only getting part of the experience of certain games, and other games were completely unplayable.
If I wanted to restrict the amount of playable games on the GC, then it was completely optional. But if I wanted to be able to play every game on the GC, and if I wanted to access all the available features of key GC titles, then I could not do this with the console alone.
All I'm saying is, if you're the type of person that would rather wait to save up for the more expensive but fully loaded 360, you might want to take into account Nintendo's history of console peripherals. Separate broadband adapter on the GC, expansion pak mandatory for select 64 titles... Nintendo has a habit of peripheralizing (yes I did just verb a word

) everything. The Wii seems rife with peripheral possibilities, especially with it's unique controller.