Playing and loving the 360 for 3 main reasons:
1) Online gaming is key for my choice in system, and, to me, there is no way Sony can compete (quality, not quantity - as in choices/options/play vs. # of subscribers) with the online-gaming giant that is Microsoft.
2) The same games are coming out for the PS3 and Xbox 360, and since I already have a 360, it would be much smarter to pay $60 to play the games I want, instead of $660.
3) I'm skeptical of the other two systems, but mainly the Wii. I already know that Sony will probably deliver (at least) a decent system, and everyone who ends up with one - and doesn't sell it for a Wii - will like it, but with the Wii system, I don't know what to expect at all.
If I get the other 2 systems, it will probably be the Nintendo Wii for my August birthday, and a PS3 sometime in 2008, if ever. Viva la Xbox!