5 Reasons Why I love Oxygen XML and you should, too
Price. $64 for Academics (I got mine as a gift from my mother-in-law: "Thanks, R!").
The save-my-bacon, I absolutely adore it, plus: Automatic Indenting. Even when I get 23,000 lines of code in ONE, long string, pushing this little button in the top toolbar will turn it into nicely-formatted and well-indented code I can actually read.
Collapse/Expand feature for long documents. A right-click on those lovely blue arrows to the left of the screen, and I can collapse thousands of lines in the blink of an eye! This is really helpful, because I have a lot of index XML to style and usually only need to see one page example's code at a time, not all 23,000 lines. You will also notice the syntax coloring in the code, a fairly basic feature, but always appreciated.
Finally, I find the code suggestion feature helpful, for all those details about an element or function that I don't want to have to look up.