VIM!! Yes it's the learning curve is a little steep, but once you figure it out you can get around really fast. And it's universal--pretty much all Unix variants have had it for about forever, and there is a really nice Windows version too.
Newer versions do PHP indenting/syntax highlighting out of the box, but there's an improved indent plugin that works even better at
http://www.vim.org/scripts/script.php?script_id=1120