many people ask me this.... I am pretty unbiased, as I like a little of all 3 camps. Here's a guide to help you choose and what I think about each platform
Apple Mac OSX:
*solid hardware that lasts long time
*can run photoshop and a lot of creative software
*the OS is secure (according to specs so far, however the increasing popularity may change this)
*you will look better in the eyes of the people that care about that kinda thing
*bootcamp will allow you to run windows on it
*lack of games
*os needs a lil of a learning curve (not too bad though)
*Os has it's customization limits
*the "hip" culture of it might turn people off sometimes
Windows based PC:
*lower cost of entry
*customization is medium
*more hardware choices
*better bang for the buck on hardware
*better for gaming
*security isn't the best, however you can secure it pretty good
*licensing costs are kinda high for consumer versions, however you may get an edu discount on that.
*to theme you need UXTheme patches or 3rd party apps.
*has crashing issues, however most are user errors.
*fairly large software avaliable
*fun to tweak and has stuff like compiz
*tons of help online
*very stable rarely crashes
*has lvie cd's/dvd's to try out before you install so you don't loose your prev. OS.
*some distros have a nice central package manager--->one place to download and install software as well as update it
*can use WINE to run windows software
*tons of "distros". new user has a high entry barrier due to choices may be discouraged
*high learning curve, but it's getting easier, much easier.
*installs can be tricky without live cd's.
*some programs still need to compile manually, a tricky task for new users
*incompatibilites with some windows/macosx networking services.
*lack of mainstream software support from adobe, autodesk, etc
*lack of serious gaming titles