Koukounaries beach is, apparently, the finest beach is Greece, and seventh finest in the world. By the first week of July however, it's hideously over-crowded and only merits a quick look to imagine what it could be like if you were the only people there.
Here's a tip - there's a completely hidden beach around the corner, still part of the same bay as Koukounaries, and just as nice. When you get off the bus, or park at the beach car park, take the track to Banana Beach. After two minutes, the road splits in two - take the left hand fork, which doesn't go to Banana. You'll end up at one of the nicest beaches on Skiathos, without the crowds.
Unique Suggestions: Everyone should go to Koukounaries, even for five minutes, to assess its claim as the best beach in Greece. Then do the above.
Fun Alternatives: As above. Oh, and it has a taverna.
Allow me to refer some characteristics which are the less impressive, striving to avoid the strong word disappointing. First of all, an outrageous, uncontrolled and still accelerating urban sprawl along the south seashore starting in the Skiathos Town and ending in the Troulos bay. All this coastal line is a row of apartments with extremely high density, so the road toward the Koukounaries is no more road, it is more a kind of street. All in all it is a mixture from huge hotels like Atrium, Esperides, skiathos Princess, apartments of all kinds and sizes and some ugly new building sites. The adjacent beaches also suffer from this tendency – they are noisy, organized, crowdy, artificial, expensive. Skiathos town possess similar characteristic. Yes, I found some beautiful corners (Mouria restaurant, isle of Bourtzi) but all in all it is more and more becoming an average town with overexpensive services and neon lit facades (you will find also McDonald s there). The spirit of Papadiamantis is hardly to feel anymore.