If you are tired or not of Courier New font within Visual Studio you should check out Consolas font. Initially it was a part of Vista and not redistributable. Fortunatelly Microsoft has decided to make it downloadable from its website:
Curiosity: It says that font pack is made for Visual Studio 2006. Go figure. I didn’t try it but I am pretty sure it would work with VS200x or any other application, too.
Another good choice for replacing Courier New is Vera Sans font. You can get it here: