What sun cream factor should I use and how likely am I to burn?

I'm from England but I have Turkish heritage and have been told by everyone that I have 'Turkish skin' because I didn't tend to burn much when I was younger and only had to use a low factor sun cream. I'm not so sure now as I haven't been on holiday for years. I'm going to Greece with my friends and was wondering how likely I am to tan/burn (if anybody knows about the skin of people in this geographical area?) Cheers