Not a regular visitor to Trip Advisor so not sure how recent this is: five hotels on Kef make the best 25 in Greece list, as voted for by TA users:
4 Trapezaki Bay Hotel, Trapezaki
14 The Magnolia Resort, Katelios
21 Avithos Resort, Svoronata
22 Apollonion Resort & Spa, Lixouri
25 Regina Dell Acqua Resort, Skala
2015 Travellers Choice Top 25 Hotels - Greece