Xbox might not be free, but it has way more players with mics, way less lag, better games, and has better options on live. It's just set up so much better. It has Call of Duty, Halo, and every other great game in the world!
Uhm... Gamecube was my very first gaming system, (besides handhelds) but I love my Xbox. I don't have to worry about having to upgrade it or anything. I love it!
Oh there are a few i LOVE:
Xbox
Xbox 360
PS1
PS2
N64
GameBoy Color
Sega Genesis
I actually bought a Genesis again recently and been playing the crap out of it
I would say PC, best graphics, easy to mod and play with, and you get to control the game a lot easier.