PS2 is the one you should go with. I picked one up this past September(May my Dreamcast Rest in Peace). I was beating my head against the wall to decide on which console to get. After much debate I decided on the PS2.
First off, there is not one game in the Xbox's launch line up that I cared one thing about. Halo is the only game that mildly appealed to me. Even if Halo was on the PS2, I probably wouldn't get it.
Secondly, There are so many games that were coming out for the PS2 that I wanted BAD such as: Grand Theft Auto 3, WWF Smackdown: Just Bring it!, Metal Gear Solid 2, ICO, Devil May Cry, Splashdown, and the list goes on and on.
Lastly, The bottom line is that the Playstation 2 will not fail. It has tons of support. Most games that come out will come out for the PS2.
Believe me I am not bad mouthing the XBox or GC, they will be fine systems in time. I may even pick one up a year from now who knows, but right now you cant go wrong with the PS2. I know you are saying "It's not as powerful as the XBox or GC" You're right it isn't, but it has more than enough power and it has the games to support it.
however if you decide not to go with the PS2.... the Xbox would be my second choice. The Gamecube just will not have enough good games coming out for it. Two or Three good games a year is not good enough.
I hope this helps you.
The fear of spiders is arachnophobia, fear of tight spaces is claustrophobia, fear of Chuck Norris is called Logic