Been with Apple machines since the IIe in 85.
Worked as an IT manager in a Advertising agency where the Artists had Mac's and the others had Winoze boxes, 98% of all the issues were with the latter for all sorts of reasons that needed time and effort to try and establish what the problem was.
OS X is extremely stable with its UNIX base (very similar to Linux but with a more pleasant User Interface, and as previously mentioned Microsoft applications run perfectly well and are easily moved between both platforms.
Consider buying a Mac Mini (around 1000 bucks) - which essentially is just the box, the size of 6 or seven Cd's stacked on top of each other with a slot loading cd/dvd drive, pre-loaded with the OS, you can add your own peripherals like monitor keyboard, mouse etc most brands are compatible even if it doesn't say it on the box...
I bought one for my parents and it comes loaded with a bunch of software for the things they really want a computer for - it has it's own web browser, mail client, digital photo software, movie making software, dvd making software etc.
Not to mention the change to Intel dual core processors to help with speed that was always seen as a "problem" with Mac
and besides - they are just so pretty to look at
My two bobs worth anyway