I use text wrangler (text editor) with cyberduck (ftp client) they work seamlessly with tabs for each file I am working on and as soon as I hit save it updates the live file. I know there are other things that do this, but none I have used has been so simple. Also when I hit F9 I see ALL my windows I have open. I hit F10 and it shows me all the windows for the foreground application that I am working with at the moment (Makes life easier in Photoshop.) I hit F11 and all the windows SLIDE out of the way so I can see my desktop. And I know you are going to say that Vista does this, but it does it in a different way (that sucks IMHO.) Adium is the cleanest IM program I have ever used. iTunes even though the program looks the same on Windows and Mac it just seems to run better on the Mac. I am using an old G4 Powerbook running at 1.25Ghz with 1 gig of RAM and I find myself just more productive for certain tasks. As for gaming, I believe you can't outperform the PC right now just because of available games. Now, if Apple made a better API to cross platform games I would rather be on my Mac 90% of the time just because I really like it. Now if you were to say that all games didn't care what platform, I would say that the platform then becomes a moot point since a lot but, not all of the hardware is the same at this point. But then it's back to the APIs because there really isn't anything that runs directly on the metal besides the OS. But to each their own, personally I don't see Mac having the edge in Multimedia anymore, but they do have a strong market in the printing business still because there is so much hardware already in place that talks the same language. As for compatibility and ease of use taking to another network I think OS X destroys Windows. It's very straight forward and powerful where as when I tried Vista (And even some instances of XP.) it was EXTREMELY cumbersome.
As for managing a network for low level CLI management I would rather be on my Mac. For managing MS servers I have RDP. For managing a lot of Unix-like systems I have X if it's available.
Also as for preloaded software. When I bought this thing there was only ONE software package that was a demo and guess what it was! MS Office. There was no crapware at all. I had programs for managing my music, movies, and photos. I had a program for making movies and dvds. It had DVD player software! It had an IM client for AOL. It has a built in program to sync with my handheld devices and phone. And it had all the things that you get with Windows: WebBrowser, Mail client, Media player, Address book. How about for the budding developers? You can download a slimmed down version of Visual Studio now... My Mac came with Xcode and has none of those silly restrictions made by MS on it.
I know this sounds like a rant, but you can't compare the two. It's not Apples to Apples. It's Apples to Windows. And you can't come off saying Mac's are just for students where is your justification for that? These are two VERY different products. Also, we all have been using the incorrect nomenclature for this whole argument. We are ALL using PCs. Some are Apple or Mac PCs and some are Windows PCs and Whatever OS PC. PC is just a personal computer.
PS I just remembered. 99% of all applications for the Mac have built in spell check from the OS since it comes with an Oxford English Dictionary and Thesaurus built in.