I'm going to try to explain if to buy a Wii or xBox 360.
Why to Buy a Wii
Wii has according to me a better control system which I like more, because it gives exercise and makes you feel more like you're in the game giving you a better game experience. And you also can go to internet and with the controls making it easier to move around on the internet.
Wii have games like super Mario and Zelda which is not that action packed as halo. It also have other games more like halo (I use Halo a lot to explain because that's the first thing I think of) but not so much.
Nintendo wii is also very small and portable.
Now Why to Buy Xbox 360
Xbox 360 offers a better graphic in games and the ability to watch DVDs at good quality. Xbox 360 also got internet through xbox live.
You can also play games from old Xbox by buying a special thing (think its hardware memory) so if you had or have an old Xbox you don't need to buy new games not all games work though but I think only the first Xbox games are those that cannot be played on 360.
Xbox 360 got more action games like halo and assassins creed. 360 also got some action free games but still they got mostly action.
This means if you want to watch DVDs and play action games with nice graphics buy an Xbox 360. If you want to play more calm games with not that much shooting like super Mario and fun controls buy a Wii.
This is all based on my knowing and opinions and as I think most people do I haven't researched about the subject.
Hope this helps you a bit.
