I'll back the Pixelmator love. Been interested in it for a while, and I finally decided to purchase it this week after the latest update. It does pretty much everything I need it to and the price was a total steal. The PSD export feature could use some tuning - a relatively small file was going to be a 48MB PSD - but I think this will be a suitable replacement for something that'd I'd have to shell out $600/year for. Just need to get some of my colleagues to also switch.
I don't do enough intensive graphic editing that I need every bell and whistle under the sun. Most of the time I am doing small buttons, or some basic cropping, touch-up ...
And for $14.99, it was an absolute steal.