jimgriff,
Look at the games you want to play and pick that way. It does not matter how good a system is, if it does not have the games you want to play.
If you want to compare the two:
The Xbox is easier for programmers to make games for, but the PS2 has more games on the market. As for Graphics, the Xbox is better. There are more PS2's on the market than Xbox's, so game makers are a little more inclined to make games for the PS2.
Take Care,
Richard
P.S. Also see what your friends have, since you will be swapping and sharing games with them.