OK Bastard the answer to your question is not an easy one. There are beefits to each system. I had a PS2 for about 3- 4 years and this holiday I picked up an xbox and Gamecube.
The PS2 has the largest library of available games than the other 2 systems but it's graphics are said to be much less pretty than the other 2 machines are capable of. The controller however is perfection especially if one doesn't have giant hands. The system is noted for it's role playing games and action games- metal gear solid, grand theft auto and others come out for the ps2 first usually. GTA 3, Vice City and San Andreas are my three favorite games on earth so - I will say that the PS2 is my favorite system too...BUT


The XBOX, is quickly catching up. They really did a nice job when they built this machine. It has a built in hard drive so you don't need to go out and buy all those memory cards like the other 2 systems force you to do if you want to save game progress. The system does seem to have better graphics but that really is too importaznt to me but it might be to you. It has Halo and Halo 2 which are not coming to the other consoles anytime soon if at all. They are great 1st person shooters ( like you are in the action) and the xbox controller is perfect for 1st person shooters- what with thew triggers built into the back of the thing.Then again the controller is a bit big and unwieldly to some ( including myself in the beginning). The cord on the xbox controller seems to be longer too which is handy. Apparently you can add music to your xbox hard drive too for customizable soundracks to certain games ( another feature I am not using but you might like)
The gamecube has a lot of their own games like the mario games and resident evil 4 has just been released for this system- BUT it is supposed to be released for the PS2 later this year so if you can wait. Also have you played resident evil before/ The movement of the character is a bit different and may not appeal to you.

Overall, I would go to gamefaqs.com and check out the different games that you might be interested in and see what systems they are out for- most times they are released across at least 2 of the consoles. Based on hardware the xbox is a little better, based on games available the PS2 wins, the gamecube is only 99 bucks though. So there are many factors to weigh and they make your head hurt which is why I bought all 3