Another reason to buy a Mac is that you want a fast Windows computer:

Quote - "The fastest Windows Vista notebook we've tested this year (through 10/25/07) is a Mac. Try that again: The fastest Windows Vista notebook we've tested this year--or for that matter, ever--is a Mac. Not a Dell, not a Toshiba, not even an Alienware. The $2419 (plus the price of a copy of Windows Vista, of course) MacBook Pro's PC WorldBench 6 Beta 2 score of 88 beats Gateway's E-265M by a single point, but the MacBook's score is far more impressive simply because Apple couldn't care less whether you run Windows."

source: http://www.pcworld.com/article/id,136649-page,3-c,notebooks/article.html