Since a lot of people are still in the dark with this, I decided to shed some light on the matter. First of all – I have tried many apps, and I do dislike a lot of things about photoshop. Mainly the price and it’s interface which actually went better in CS4, but in general is bloated and not intuitive at all. Oh and did I mention that some universal things don’t work in all adobe apps? Like alt + scroll wheel doesn’t zoom in / out in Flash. How cool is that when they’re selling it as a very pricey creative suite ? Well anyways, I do use photoshop at work and it has a lot of advantages over the rest of the software mentioned, but for most of the time, they’d do fine. Because the tasks photoshop is better at are usually those rare ocasions. I’ll focus on both PC and the MAC and talk about two alternatives that I think are the best as far as price-to-features ratio.

PC world : Corel Paint Shop Pro Photo
This is a very close one to the photoshop killer. Mainly because it’s more intuitive and the price is a couple of times lower. There are things lacking though, like a good handling of layer groups, layer styles and more. But the thing lacking the most is a good text tool, with plenty of options. Sure there are quite a lot, but the resulting effect is odd for some reason. It does not render text nicely at all. If you’re making a website, that alone can make a difference between good and bad layout. Sure a lot can be done in it, but the bad text rendering and no “justify text” option are likely to become drawbacks while designing. I did use this software for a couple of years though, because it was a lot cheaper and had most of the same possibilities. Still like it and I think you should try it for it’s price.
Corel PhotoShop website

MAC : Pixelmator
At 59$ you can’t really ask for a lot of features. But you get them anyway. A great painting engine for tablet devices, fast and reliable, cool looking interface. But there’s almost no text-tool. I mean it’s so basic it’s like it’s not there at all. And there’s no grouping of layers or layer styles so that makes it a lot harder. But the pixelmator team is working hard on it, so I guess they’ll eventually add all those things there, just like they’ve recently added an amazing save-for-web feature. They do think a lot about the interface, and speed / ease of use and that’s a big big plus. It’s got about 80% of what a webdesigner needs right now, and I can’t wait for the new versions.
You can get it at pixelmator website