WildBob pretty much nailed it. I have a Wii and a 360 and I think that I would want to play "traditional" sports games with a more "traditional" controller. If you get a Wii you'll be using a pointer and nunchuck, one in each hand. Don't get me wrong, it's very cool, but I don't think I'd prefer it any more over a traditional layout with a D-pad and a thumbstick. If you're coming from PS1, that's what you're used to.

As stated above, the 360 has the best library of games and the best online service. Xbox Live will run you $50 for a year, but it's worth it. Get the 360 Premium, Xbox Live, and Madden and you're looking at about $500.