I'm just now switching from PCs to Macintosh. I bought my 6 year old daughter a little iMac G3 on eBay a week ago. Safari 1.0 on that iMac seems to run BITOG better than IE8 on Vista (I get weird activity in the reply text boxes with IE). I'm amazed at how efficient the Mac OS is. This little iMac is a 600 MHz processor with 512 MB of RAM, and graphically, it's similar to the most modern versions of Windows. And you couldn't get the same performance out of a 600 MHz PC. And every new version of Mac OS seems to be faster on the same hardware, which is opposite (in general) from Windows.
I'm also getting to the point where I appreciate a nice design as much as gut performance, and I'm really considering a new iMac purchase to replace the Dell mini tower we have. Nothing wrong with the Dell, but I think it's just time for something different. The more I look at Mac stuff, the more I like it. Software seems to be cheaper overall, few-to-no virus issues, excellent built-in productivity software in Snow Leopard, and no endless Windows Vista/Windows 7 security updates. Ease of use is also superior in my opinion.
Back when I built computers for a hobby, I thought Macs were only for turtleneck-wearing artists. But as I've grown up and left the computer constructing hobby behind, I can more appreciate what Macintosh offers.