I purchased Pixelmator back in 2011 during one of their early promotional sales. It's taken me this long to actually sit down and see what it has to offer. (Note that I've been using Photoshop for over 15 years, so it has been extremely easy to just glance at the Pixelmator icon and think "I'll try you next time.") Well, now that I've tried it, I have made the decision to keep using it whenever I can. The feature set is outstanding for a $30 piece of software. It's also very user-friendly from a Photoshop user's perspective—almost every function and keyboard shortcut I tried worked the same as it does in Photoshop. Hell, it even lets you open up layered PSD files! As far as I'm concerned, if you have a Mac and want an image editor, this is the app you need to look at first.
Here is the result of my first trial run. I just took an old black-n-white drawing I did back in college and started fooling around.