the 360 has better graphics and will have halo 3. The game that made me almost get a wii was Red Steel, and my friend told me it wasn't that good. I might get one as better games come out but as for now the 360 is great. Crackdown is another cool game coming out for the 360 in 6 days.
Wii OWNS xbox360, sure nintendo hasnt always had the greatest graphics out there, but its always had the best game play. Xbox are just another wannabe, like Sony, sure they have some good games... but could you really compare viva pinata to zelda? I think not -_-
In my experience it really depends on the types of games you like to play. I love the 360, it's got all kinds of games that I'm into. Though the Wii will have them in not to long either. Wii plays harder, 360 is easy. I'd pick the Wii though!!!