MAC OSX (Tiger and Leopard) all the way fellas... Don't forget we can now run those windows apps and those linux apps too!!!
For the money, you can get yourself a fantastic iMac... Unless you happen to be working in various locations then I would stick with an iMac.. Wouldn't mind a MacBook Pro for my travels.. All 10 miles of them...
Like the look of Linux, but lack of support for Monitor put me off.. Would still use and indeed the schools here use it throughout the IT depts. | 
