OK, so UltraEdit is not that expensive and I have yet to see an unfavorable opinion of it. But Notepad++ works fine for me, and as of today it works even better.
Like most everybody, I indent my code. I use tabs for that. Tabs are convenient, but they are set to different widths for different systems by default, and that can be annoying. For sets of nested curly brackets three or four levels deep, which between loops, if/else conditions, and function definition syntax can easily happen, wide tabs can make your lines run over the width of the screen.
Notepad++ can fix that. In the "Settings" menu there's a "Preferences" item, and in it there's an "Edit Components" tab. In it there's a tab box, which gives you exactly the two options you need to solve this problem once and for all: the first is the number of spaces equivalent to a tab's width. The default is 4, which is also the preferred width of at least one widely used coding standard -- the Zend Framework, for PHP. The other option is a cool little check-box that reads "Replace by space".
You check that box, and your friends who like indented code but hate tabs will love you.