I have a wii and a 360,,, both are equally good...
Good for 360
Graphics are awesome if you have a HD TV, or run it through your PC monitor.
Some games you just cant stop playing.
Easy online gaming
Bad for 360
Online gaming comes at a price (for subscription)
If your broadband provider has clamped down with "fair usage policy" then it meens you could end up paying alot more for bandwidth you didnt even know you were using.
price tag for games + console.
Good for wii
Totally new controller, new way of playing games, not just same old games with better graphics.
Graphics are not that bad.
low price tag.
ANYONE can play it, seriously, have a look around, people have reported that everyone in their house is playing it, even those that have never played games in their life.
Bad for Wii
Small list of decent games (for the time being)
No online gaming (for the time being)
Lots of games are based around minigames.
may find it hard to play a single player game if youv got a big family, cos everyone will want a turn :S
Also, just something i have to bring up. as people were talking about FPS' they are MUCH easier to play on the wii, move with the stick, shoot with the wiimote... simple. you dont have any trouble aiming, or trying to line up a crosshair using two analogue sticks (i hate FPS' on the 360/ps2)