Welcome to the forum thomaswos, good topic
I've used both PC's and Mac's. My main computer was on Windows up until about 2008, since then (so for nearly 2 years) I have been using Mac OS X. I like both operating systems for different reasons.
Windows
I like Windows a lot, I have used Windows 95, Windows 98, Windows ME and Windows XP (never used 2000, Vista or 7)... I had even used Windows 3.1 a couple of times back in the mid-90's although (never owned a PC with it though). I don't understand why so many people dislike Windows, because I have never had any major problems with it. Perhaps I have been lucky
What I like most about Windows (especially ME and XP) is I am so familar with it - I felt there was a learning curve going to Mac. Just simple things like ejecting a CD from the drive took a while to figure out in Mac (having to click the Eject button in the Finder window, or pressing the button on the keyboard - as opposed to pressing the button on the disk drive on a PC). Also, I like some of the applications for Windows better - things like SmartFTP and uTorrent on Windows are better than their Mac equivalents. This is just a personal preference though.
My favourite thing on Windows though is that it tends to be more compatible. For example, watching cricket streams - not easy on Mac because the software is not available. But on Windows, just a couple of mouse clicks. I guess as Apple gets a larger slice of the market share this will change though.
Mac
My iMac is faster than any Windows machine I have used. It freezes less, and when an application does freeze it is generally easy to get out of it. I remember on Windows the application stops responding, the screen goes white, you go Ctrl+Alt+Delete, click End Now... the End Now window freezes, you try to quit that, etc, etc... On Mac it is a lot quicker to end an application. Ctrl+Alt+Escape, force quit -> done.
Also, Mac is based on Unix, so it comes with a lot of the benefits of Unix. Java, Perl, C etc all come with the operating system and can be run very easily from Terminal.
I love the way my iTunes is set up on my Mac... the integration between iPhoto, iTunes and my iPhone is seamless. For multimedia Mac is great. I don't know anything about photo/image editing, but I believe a lot of people choose Mac for this.
Verdict: I like Windows better, because it does more for me. Just simple things like having a lot of ports (like S-Video for one) in the back, as opposed to the very few in an iMac.
On any given day, a Mac is probably better because it is superb for listening to music, browsing the internet, etc. However, for those times where I want to do something more with my computer, I'd prefer to use Windows (and in those situations, I get my XP laptop out)