I'm biased against Gamecube, the only good exclusives IMO are Super Smash Bros. Melee and Mario Kart Double Dash. Those aren't enough to carry a system, and Shigeru Myamato (I probably butchered the spelling) is way too full of himself and no longer has any good ideas. Also they don't get many of the games that are on both of the other systems.
PS2 has the best exclusives (Jak, Ratchet, Getaway, Maximo, Mark of Kri, Final Fantasy, San Andreas, Time Crisis, Kingdom Hearts, Sly, etc..).
XBOX has less exclusives (Buffy, Halo 2,Dead or Alive, Fable, Mechassault, Crimson Skies, Midtown Madness, R63 BA) , especially if you consider games on PC not XBOX exclusive (I do), but it generally has the best version of most games and most great games come to both PS2 & XBOX.
EDIT:[quote name='btw1217']If I had to choose, I'd choose Sony. But those damn Disc Read Errors are making me question that. Cmon Sony! Spend the extra dollar to make our systems work properly!! ](*,)[/quote]
I have had much more trouble with XBOXs (3 Broke), and Sony does offer Free Repairs (if you ask for a replacement you'll get a free controller, AC cord, and AV cable).