I wrote the following message for FredFredricksons blog post "Torn between Wii and 360", only for it to be turned down because of it's length:

Well lets talk about the Wii, yes it is cheaper, which is a really good thing, but still rather expensive, your arm will be very sore after playing long periods of time swinging that controller around, and you are more or less holding your arms in front of you the whole, pretty tiring, but you could probably actually say that you are gaining reflexes, cool.
Now lets talk about the 360, its nice, and I'm currently earning one, but when I finish earning it, I will enjoy it, I'm planning on getting Gears of War, seems to be getting good reviews. And another thing is I get to play the Halo series, plus there will be Mouse and Keyboard vs Controller, so if you thing controller is better, you can now find out.
You can play your music during your games, so instead of listening to the same groove, while you race through downtown L.A. or San Fransisco, or Tokyo, you could listen to CKY and have a ball. Though the games are expensive, I'm pretty sure they are mostly worth it.

your arm will be very sore after playing long periods of time swinging that controller around, and you are more or less holding your arms in front of you the whole, pretty tiring