I run Windows 7 on my iMAC as there are a couple of programs I use regularly that are not available on a Mac and there are no Mac programs I can use instead. Otherwise I would never use Windows again.
Mac Snow Leopard £25.00. Microsoft Windows 7 UPGRADE £69.00.
When I bought my iMAC it seemed expensive but looking at the spec it is cheaper than many flat screen all in one PCs from HP, Sony, etc. and they do not have the fantastic 27 inch 2560 X 1440 screen, 1 terrabyte of HD, 4 Gbyte RAM, Hi Speed Firewire and the ability to boot in about 20 seconds and run most software as quick as clicking the link. Also it looks good enough to keep in the living room. In fact we do and it makes a very attractive digital TV with built in recording for the extra cost of £50 for a USB dongle.
Windows 7 on my iMAC and laptop work well but doesn't come close to the speed and ease of use of my iMAC