hi there, from my experience and opinion alone, i would suggest rhodes. there is much more opportunity for sight seeing (lindos acropolis etc) lots of towns and villages to take in if you get yourself some wheels, a great waterpark for the kids in falaraki, and i believe there is also opportunities to dive in various areas, although i am not quite sure which resorts exactly. you also have the option of a day trip to turkey if that takes your fancy. there is also a good variety of resorts suitable for the family such as lindos (which is traditional, historical but boiling in th summer months)and pefkos, or maybe try ixia if you are after a larger hotel with more amenities for your kids such as kids club activites. saying all that, corfu is lovely depending on your resort, the beaches are fab but i think rhodes has a little more scope for sight seeing, history and other days away from the sand, hope this helps you a little