Yes, I kept the PS2 box. I keep all the boxes and instruction to every system, game, and accessory I buy, including, for systems only, the foam inserts, etc. There are only two cases in which I couldn\'t, due to reasons beyond my control: My original Gameboy box, from 1989; and my Atari 2600 box.
It\'s just better to keep them, if you can. That way, when it comes time to store the hardware away, you can just pack \'em up real nice and neat. Plus, it\'s just cool and nostalgic to own.
Frodo