Not sure if it was in this thread or in another one about a similar subject, but I've made it no secret that I absolutely despise Eclipse based IDEs.
A few months ago I got a Mac, and despite still being happy with nuSphere PhpEd it was time for a change as I wanted to use the same IDE whether I was on Mac or Windows and PhpEd is native to Windows (it's not Java based).
So I did my usual trick of trying everything ranging from the free to the premium none of them were for me. Specifically Eclipse PDT, Zend Studio and Aptana were my main gripes. Predictably I had the same or similar issues in all of them, which is to be expected being the same underlying product.
My main issue is relating to the overall performance of these applications. I won't go into details but it's the same kind of thing I've had before. There's probably various settings and optimisations available but I'm a firm believer in the fact that things should just work.
Speaking of which, that brings me on nicely to the IDE that won my heart and I am actually spending my money on:
http://www.jetbrains.com/phpstorm/
I think it's been suggested in here a few times, but I overlooked it. Now, I think it's fantastic.
I now get the same development experience whether I'm on PC or Mac and it has some killer features and it's just a pleasure to use. I actually now do all of my HTML, CSS, JavaScript, PHP and MySQL stuff entirely in PhpStorm.
So, highly recommended if you're bored of your current IDE