I'm what people would consider a power user on both platforms. I build my own PC's and currently have six of them in my house and have never bought a brand name. My platform of choice, though, is the Mac and have several of those as well. I use my Mac Pro at home for virtually everything and nothing slows it down. I can render videos for my media server at better than real time, surf the web, run email, run Aperture (a professional photo management app) and run Parallels with Windows all at the same without that computer breaking a sweat. And it's rock solid, too.
On the other side of my desk is my personal Windows Vista machine that gets turned on maybe once in a blue moon.
When I'm away from my desk, I have my trusty MacBook Pro with the gorgeous 15" LED glossy screen. Why can't PC vendors make a laptop that isn't ugly?
For those who need Windows and like Macs, the Intel Macs are the ultimate computer (sorry M5). You have several different ways of running Windows for those programs that just don't have a counterpart on the Mac side. For games and speedy 3-D graphics, Apple makes it easy to install Boot Camp on a partition of your drive or a separate drive on a desktop machine. Booting into it gives you a fully functional Windows machine with no Mac OS. Many stories you read on the web will tell you that Macs run Windows better than most PC's do, and faster too.
If you want Windows side-by-side with Mac OS, there are several different options, the two most common being Parallels Desktop and VMWare's Fusion. Both are excellent products and run Windows programs quite well. In fact, both PD and Fusion have modes that hide the Windows desktop so it looks like the Windows apps are running on the Mac desktop and are fully compatible with OS X's Expose. The latest Parallels beta (build 5148) even has the option of showing your Mac documents, pictures, movies and music folder in place of the ones you would normally have in Windows so you are essentially using the same home folder in both operating systems.
For those who don't want to pay Microsoft a dime for a version of Windows, there's CrossOver, an app that came out of WINE (self-referencing acronym that stands for WINE Is Not an Emulator) that essentially emulates the Windows programming interface allowing you to run Windows programs without Windows. What it does is translates Windows programming calls (aka API calls) into the Mac equivalents and it does it at nearly full speed. It isn't fully comprehensive, so check CrossOver's list of supported Windows apps before you buy it.
I wouldn't even run Windows except my development tools only run on Windows (I'm a software engineer using Visual Studio 2005).
I also have a little Mac Mini that sits in my media closet acting as a media server streaming TV shows and movies to my Apple TV's. I've ripped hundreds of my own DVD's and placed them on my Mini with two terabyte hard drives and can watch them on demand.
I also recently converted my wife to the Mac (she's on her second iMac - one of those awesome-looking aluminum 20" iMacs) because she loves using Aperture to make photo books and Photoshop for photo editing.
For those who need Microsoft Office, the one on the Mac isn't very good and isn't even Intel-native, but then why would Microsoft make Office for Mac a top priority? Consider this... iWork '08 and NeoOffice for Mac (free, open source app that's way ahead of Open Office and was written from the ground up as a Mac app instead of having X11 roots) both support the file formats that Office 2007 for Windows uses while Microsoft can't even write a decent translator for Office Mac 2004, which shamefully doesn't support Office 2007's new formats. The new Office for Mac 2008 is expected to ship in mid-January.
If you really need Office, though, you can always run it in Parallels or Fusion. That's what my wife does since Entourage is bad even for a Microsoft app.
As for the iPod touch, I already have one on order, shipping by September 28 and delivered by October 2. I can't wait and am already counting the hours. Who cares about the iPhone with its 2-year contract with AT&T and the pathetic EDGE network? <g> Karen's right that the 16GB is pretty paltry, but I'm sure I can make do even though I really want it for photos and videos and, of course, web surfing through WiFi. Meanwhile my old iPod with the 60GB hard drive will stay in my car.
