Weed is the most socially accepted drug and easiest to find, though quality varies for crappy shit from Albania to quality from Kalamata as discussed before. Coke is popular, maybe to popular which kind of makes me avoid certain areas in downtown Athens, to many egos fighting for the same attention, the newly rich, or neoploutoi in Greek. Mdma, acid and ket were very popular around 97 just up until the Olympic Games when the police got to serious and clamped down on all those scenes, closing clubs and raiding events i.e. places like Oinofuta, Alsos, +Soda. Still out there, but very limited and you could say pro coke propaganda has also influenced the way people think about drugs. Heroin is the easiest drug to score, open air scene in Athens with Afghan and Nigerians selling even outside large retail stores. Don't use so do not know about the quality etc, as I know you do from your posts, but deff no drought in Athens, people shooting up and nodding in the run down parts of the city.
Compared to other parts of Europe that I have lived in, yes the usage is definitely much less, maybe the percentage of heroin users is the same, a tad bit less, but when it comes to everything else, much lower. People don't even drink that much and is very evident when the bars close as you don't have many drunk people wondering all over the place, fights etc. Islands and the summer are a different thing, but in urban environments people are to afraid to let lose some times and hold back...