I don't think it's any of those.
I think it's the best use of hardware. People loved how the PS1 played on discs, they loved how the PS2 could play DVDs and was one of the cheapest DVDs on the market (especially in Japan, where I think it was significantly cheaper than any other DVD player, but I could easily be wrong about this).
And people loved the motion controls in the Wii.
I'm really caught between that and thinking that the "Killer app" is the #1 choice. Look at Halo, look at Wii Sports. The other great games will follow once the big boom sets the stage and grabs the attention.
I may come back to revise my choice later, but ima go ahead and throw this out for now to spark a discussion.








