If you are Greek and you want a place for all day parties, Mykonos is the island to go! The village are picturesque and I loved the small paths of the island... Perfect beaches with both loud music or quit corners...The beaches of Ornos and Paradise were great, lot of beach sports and lot of dancing!
Visit the cafes and the bars in Little Venetia. Nightlife on
Mykonos is good but I would like it more if all the restaurants did not refer to Italians. It is perfect if you know where to go and as a Greek I did. But it is more difficult for foreign tourists, since they usually stay in Chora for food, where most of the restaurants are touristy and not traditional. You should better visit smaller villages, such as on Ornos. The bad thing is that it costs more, but it's worth it.
Also, more taxis is something that has to be done on Mykonos. Once you are there, you should watch out for the drunken drivers. August is the best period to go or at the opening and closing parties. Also nice at the beginning of May, when university students go as it is cheaper.