Try installing the "xfonts-terminus" package -- these fonts should look good in terminals.
Also check out that you've got the general font settings OK. Do (as root) "dpkg-reconfigure libpango1.0-common" and entrust font management to defoma. If you've got msttcorefonts installed, you need to have the following line in the "Files" section of your Xserver config file:
You can also do (as root) "dpkg-reconfigure fontconfig" and select the "Autohinter" option (and subpixel rendering if you've got a LCD display). You can also do (as root) "fc-cache -fv" to make sure that all the installed fonts have been registered.
There may be some additional things you need to do in KDE but I don't use KDE, so I wouldn't know anything about that.