DVD-R work fine for me. I have used +R also, but it is not worth the extra cost as I see no difference. -R is for general use. +R is for master disks. You can get them for a little over a buck a piece <a href="http://www.cyberguys.com/templates/SearchAll.asp?search=dvd%2Dr&child=&curpage=2&ureq=y">here</a>, Cyberguys. Add some shipping it is still a good deal.
An explanation of -R, +R, RW, DVDRAM is <a href="http://www.dvdrhelp.com/dvd"> here</a>.