In particular, I don’t. Lots of times other developers come over to me and look confused as they see Tahoma, 8pt. They have all sorts of comments about it not being right, in fact my absolute favourite was that it a waste of memory. Sorry last time I looked, Tahoma 8pt is the font used everywhere else on my desktop. Windows is probably saving memory by sharing it around.
However the problem is that some applications don’t let you make your own decisions. VS2003 only ever allowed you to get a bold variant of some Fonts e.g. Tahoma, but some other applications go one step further. They only let you access a fixed width font.
Sorry, but these applications are making a decision that should be theirs and they are choosing to affect my productivity. There is considerable research into what makes text faster and easier to read (i.e. you make less errors when you read it).
So given all this research (apologies that its all from one source) why do so many applications force you into fixed width fonts!