I'm not getting the 360 tomorrow, but if I were, I wouldn't settle for the core.
Wireless controller: It's next gen, we gotta seperate from that wire. Wouldn't you feel stupid using a DVD remote with a wire?
Hard Drive: I'd rather pay the 100 for the hard drive, since the memory units are probobly 40$.
Free 1 year XBox live: I want to play online :) The best part of haveing a XBox 360 :)
Headset: Another thing that you need for the 360, to really enjoy XBox Live :)
HDD cables: I don't have an HD tv, but I'll get one eventually.
Remote: Would really be nice :)