HDMI will give you the best picture right now, then comes VGA which can do HD up to 1080p too, and the regular component cables that max out at 1080i
you will see a huge difference between regular a/v cables (yellow, red, white) and hdmi
you won't see that big of a diff between vga and hdmi
and you will see somewhat of a difference between component at 1080i vs hdmi/vga at 1080p
but I say its def worth it to get the 360 with hdmi out
