For things like editing rooms.xml a fixed width font like Courier New is obviously preferential, as otherwise you can't tell at a glance what is above what BUT to me even this seems inadequete. I've yet to find a font wherein, in addition to being fixed width, the lines are exactly the same height as the characters so that the definitions for the rooms aren't stretched out in the text editor. Does anybody know of such a font (and/or a way to achieve this effect in Notepad++)?
Try Lucida Console or Monaco. I usually use Dashcode(Mac Only, from X-Code), so I don't have that problem.
I did some poking around after I posted this question and found a site with downloadable fonts that had a couple that fit the criteria I was looking for: http://www.dafont.com/theme.php?cat=503&page=1 The fonts "Futurist Fixed", "Speculum", and "White Rabbit" all seem to satisfy my criteria (unfortunately they're all hella hard on the eyes)
I do a lot of programming and I've found one font that I pretty much can't live without. Give this one a try and let me know what you think! http://www.levien.com/type/myfonts/inconsolata.html It's not exactly what you're looking for, but it's really easy on the eyes.