To me, the gaming disadvantage is not even close to make me even think of considering a PC instead of a Mac. Unfortunatly I have to use PCs at school, and I find them extreamly inconvenient. I have of course been a Mac user since the age of three, but for this post I try to be as objective as possible.
One-button mouse situation:
On a Mac ctrl-click has the same function as right-click (you can of course use a multi-button mouse if you still prefer that). This makes me frequently sit with my right hand in a typing position, inviting me to sit in a more ergonometric/healthy position, and makes time-saving keyboard shortcuts much more inviting. I never get wrist or back problems when using a Mac, in contrast to PCs
Easier development
I'm not a very good programmer, but I can manage most things with the applications that follow with the computer, such as an elaborate IDE (Xcode) and every other tool you need (They should port ResEdit, even though it's somewhat obsolete, but I liked the hex editor). On Windows I have to do with Notepad without spending extra money.
User interface
This is slightly subjective, but I have a hard time believing that people will prefer the boring grey or annoying ill-proportioned sharp blue of XP to the harmonic Aqua interface.
And besides, I have everything I need available in editable toolbars, but on Windows many of the toolbar items are just in the way.
Unix core
Many scientific applications are written for Unix. This makes them work on Mac.
Unix is basically flawless. No security leaks, practically no crashes, exellent server capabilities (I run a http/MySQL server from my home computer without any problems). All this with the easy-to-use interface of Macinosh
Included apps
Mail vs. Outlook: Mail has everything I need when I need it, and it handles spam flawlessly. Outlook is slow, and often my real mail is put in the spam and spam in the inbox.
Safari vs. Explorer: Safari hasen't the toolbar cluttered with things I hardly ever use, which belongs in the menu. Safari has built-in Google search, Explorer has built-in msn search. Safari shrinks printouts to fit the paper, Explorer leaves out mutch. Safari displays everything according to standards, Explorer is non-standard. Safari is faster when it comes to Applets.
iChat vs. MSN: When I use IM I want to talk to people. Not play stupid games, mess with avatars, be signed out all the time. I want to have all my buddies in a very readable list, with no confusion of changing nicknames (however you can have an 'available message' that replaces msn's ever-changing screennames). iChat fulfills all these needs. Too bad so many other ppl uses msn here in Norway...At least you can have both AIM and ICQ buddies.
QuickTime and iTunes vs. Windows Media Player: Quicktime plays back the content without any fuzz, Windows Media is slow and unresponsive, and the Windows version is cluttered with features other than playing back the movie I just double-clicked on or opened from the internet. iTunes is logically arranged with artist/album/genre columns, in WMP you got to be patient. In iTunes you import and burn CDs in a matter of mouse clicks, in WMP in a matter mouse clicks, uncertainty and wait.
Text antialiasing:
What is text with ugly stairstep edges anyway? Oh, I remember, that's the stuff on PCs whithout some expert having some setting enabled somewhere.
Wizards:
I'm not dumb, I know what settings I want to make. Why can't XP respect that?
Support for disabled people:
(note that I don't use any of these features, and therefore has little knowledge of Windows equivalents)
Everything, I repeat, everything is written in clear print, with a non-cluttered background for those with poor eyesight. If that's not enough, a couple of keystrokes zooms in on it. For people who can't manage pressing a bunch of keys at the same time, a feature can be enabled to allow pressing key commands in sequence instead
Edit: I was in a hurry to catch the train, made a couple of rather retarded mistakes...
