Good Inexpensive Media for LG GSA4120B in UK

I am a newbie to DVD burning and am looking for good quality but inexpensive media for an LG GSA4120B burner in the UK. I am not looking for high speeds but It must be reliable and work on a Toshiba SD330E DVD player.
Does anyone have any experience / recommendations regarding what type ie DVD -R or DVD +R etc and what makes would be good. Also where would be good places to get it from.
Regards John