Maximum PC

Hey, I'm in the market for a new computer, and seeing as I'm doing my Jr. Year in Japan, I need a small one that I can take with me, so I'm either getting a notebook or one of the form factor PC's.
First of all, what would be the advantages of either over the other?
Also, I was at a friends house, and he's a big gamer, so he pointed out his friend's computer, which was the one some really good clan used or something.

Basically, I was wondering which form factor PC was the best, and if you can make one on your own with normal desktop parts.

Thanks.

The great thing about SFF cases is that you can put regular desktop components into a MicroATX motherboard and be good to go. You get the upgradability and expandability of a desktop (though more limited) and you get the small case.

I would rather have a SFF PC than a laptop, if only for the much better expandability/upgradability (read: you can upgrade the video card!).

Notebook for the simple reason of portability. You cant take a SFF to class.

really no comparison, portable, the newer notebooks are upgradable.

sff is fine for a lan party or to save space. but add the monitor to what you have to carry around, and a keyboard, mouse in your pocket

notebook