I’ve been using PSpad for editing my php/html files for a long time.
It is by far, the easiest to use for me. It is small and doesn’t take a lot of resources to use. I utilizes syntax highlighting and has all kinds of features.

Notably the features I cannot find elsewhere:
1. Put the cursor on a bracket ‘{‘ or ‘}’ and it highlights the mate for it in the document.

2. Put the cursor on a <div> or <form> or most any element, and it highlights the closing tag for it.

I wish it worked for the new HTML 5 elements like:  <section>, <header>, <aside> …  Maybe in a future revision, I hope.

3. I can select a bunch of code and remove the blank lines with a menu item or a keyboard shortcut.

4. I can select a bunch of code and either ‘tab’ or ‘shift tab’ to move right or left by a tab increment.

It supports themes for displaying the code. I recently had to change the color and highlight of the currently selected line of code.
I finally found how to do that:
Menu View / Active line – to turn on/off highlighting the current line.
OR
Settings / Program settings / Colors / Current line /

You can get the PSpad editor at http://www.pspad.com