This is a great time to buy an x-box. Fable is being released today and Halo 2 is about 2 months away.
I am seriously thinking about getting Live just for Halo 2. It looks great, and bots will not be included so Live is the only multi-player option other than system link and just having friends over.
The controllers are great, whether you want the older Duke controller or the smaller more compact S-controller.
Also, I can't say enough about the custom sound-track feature. I rip songs onto my x-box hard drive and can play then in some games, i.e. NFL 2k5. It has this great feature where you can create your own stadium music.
Anyways, I'd recommend buying one, since this is the cheapest it will be until the X-box 2 is released sometime next year.