So which countries are more preferable? And from where do you have this information?

People from Europe & Oceania (Australia, New Zealand, etc.) get 80% of the DV. If you're fromm elsewhere you have around a 1% or less chance of winning. (For Oceanians it's about 5%.)

Source: Wikipedia article on it.

That's not right. The chances of winning are, with the exception of Oceania, less than 2%. http://en.wikipedia.org/wiki/Diversity_Immigrant_Visa#Winnin... (Oceania is 5.28%). I'm not sure where you got the 80% from.