Last weekend I visited Sifnos for a wedding. It was the first time that I've been to the island and some friends proposed me to stay at Verina suites and they were right!The hotel is situated at Platis Gialos and is only 2 minutes walking from the beach, where you can find many beach bars (kalimera is the best!!!) and restaurants with traditional food.
The rooms are big enough having all the modern amenitities and a sense of "personal touch" that makes you feel very comfortable from the first moment you get in. However, my best moments was during the sunset when i was drinking daquiri coctails at the swimming pool of the hotel.. This i liked most in this hotel was the staff, some young guys around 30's, without any formalities that were very friendly and helpful...
I spent three nights there and it is from the little times that i want to visit again the same place and I am planning to do so.. if you do not take your car with you it is good to rent one because the buses are very rare and it will be difficult to visit different places.
I higly recommend verina suites and i am sure that especially for young couples and groups of friends is the best choice