Which one do you think is better?
I'm kind of new to IDEs, but I've wanted something that can pick up my functions, so I dont have to scroll up and down to remember what I wrote long ago. Text Editors can only do so much 
PDT vs Aptana Studio
8 days later
I use aptana myself, show me where can I find PDT and I can tell.
(btw, Aptana does pick up functions)
download link for PDT - when you go here, click on the latest stable build, then you can get the all-in-one (thats the one I get)
PDT is supposed to replace PHPeclipse (which is dead)
13 days later
I personally think Zend puts out the best IDE. And now with their "base" on Eclipse, it really beats PDT out of anything.... just my honest opinion. If you're going to pay for it, may as well try and get the best.
Download them and try them out. Zend has a 30-day trial, I'm sure Aptana does too. Test them out, see which you like better.