Pixelmator is going to be your best bet for a Photoshop alternative on a Mac. It's far faster, more beautiful and all-around pleasant to use, not to mention the

Pixelmator is going to be your best bet for a Photoshop alternative on a Mac. It's far faster, more beautiful and all-around pleasant to use, not to mention the original was built by just two brothers and I like supporting smaller teams that actually use their products (something I wonder if a lot of Photoshop developers do given the issues that are consistently not addressed with each release). It imports PSDs, but last I tried, it had trouble with layer styles.