Here is my evaluation of the whole point.
Gamecube = R.I.P.
PS2 = Was once a god, but is now withering down to be owned by the XBOX totally. Mix crappy online play support with a really crappy system, and the XBOX just annhilates the crap out of the PS2.
XBOX = The best console system out to date. Great online play (XBOX Live), Awesome system power (best of all 3), Stability (discs rarely stop working as they tend to do alot on PS2), and a new low price. If you want a great console, you can never go wrong by getting an XBOX.
PC = VERY VERY VERY VERY VERY VERY UNDERRATED. Sometimes it really makes me mad how underrated the PC is. It is, no doubt, the best, and I mean BEST thing you can play games on. Consoles play no role in the battle against PC's, and with a PC, you can do literally everything. Literally perfect online support, awesome graphics if you can get a good video card, superb games (Doom 3, Half Life 2, Far Cry - you name it!). The PC is almost always left out of gaming conversations - at least where I live, and this really makes me mad. I think too many people are "afraid" of trying out a PC because they do not believe that they are capable of putting up with the "high-tech" stuff that PC's offer and upgrading options. An example of this is how I am the only person in my school who knows what a video card is - at least this is what I get out of talking to almost everyone in the school.
So overall, the PC is the best gaming platform you can get. The XBOX is great as well.
The PS2 still has a little bit of life in it.
The Gamecube - well, lets just say it brings back those Dreamcast memories of a system that tried at first, but whithered away before long..