Well, I see Mac as a more creative platform, whereas pc (or Windows) is more business to me.
Personally I don't like Windows very much, but I'll give you my ideas of hardware and OSses:
PC:
- Flexible, you can choose most any hardware and software
- Possibly unstable, depending on your choice (DIY or one of those HP's for example)
- Less limits, you're not tied to the manufacturers list of components
Mac:
- Stable, it's pre-build and tested to work well
- Limited modification options, you could be tied to the hardware the manufacturer offers
- Spiffy designs, it looks nice
But since Apple switched to Intel, there's not that much difference between the two anymore.
Windows:
- Most software is build for Windows
- Most virusses are build for Windows
- it could get, because of the above, a little buggy sometimes
- it works great for office apps and you can find just about any type of software for it
Mac:
- Sleek design, userfriendly
- Stable, unless you install buggy software (but I noticed the system itself keeps working still)
- a little more limited choice of software
- limited configuration options (mostly in the user interface, i.e. window handling and theming)
- great for creative work like graphics, movies and music
- office apps are a little weak, although you could install Microsoft Office..
If you'd like to get a little creative or just hate to do a little work to get a secure and stable system, I'd go for Mac.
If you need to do much office work, want to try out many types of software, or play games, I'd go for PC.
DISCLAIMER: The stability and safety of a system most of all depends on the sysadmin. I am also aware that there is really alot of software available for Mac, good software too, something for every task you can imagine, but quantity wise, Windows wins on that area. Hardware differences and stability are getting more and more thesame now between PC and MAC, since Apple now uses Intel systems.