Changing Fonts in the Finder


I've somehow managed to change the display font in the Finder and I have no idea how.

Both my desktop icons (the HD images and any icons I place on the desktop) and my Finder windows are now using different fonts (I think) and look very ugly.

I searched through the system prefs but I can't seem to find where the change may have occurred. Any suggestions?

P.S. Has anyone tried deleting some of the fonts that came pre-installed? There are a ridiculous number of completely useless fonts that are just cluttering my font menu. Does any bad happen? Should I keep a backup copy just in case?