I am not a hardcore PHP developer, but eventually I deal with writing, fixing or managing some PHP code. Recently I got in development of custom Drupal modules so PHP appears to be my primary language now.
I should say I am old fan of Eclipse IDE. It is my only IDE for Java development since 2.0 version (2001?) and also for Python some time ago. Because of my sporadic PHP experience before, I never had an idea of using Eclipse for PHP development but the time has come and I installed PHPeclipse plugin.