Croatia
I just spent 2.5 weeks in Croatia and it really is a beautiful country.
I started in Zagreb and then travelled via Plitvice Lakes to Split. Sailing from Split to Dubrovnik is the best way to discover the islands off the coast and a minimum of 7 days is definitely recommended!
It is also amazing how many countries you can visit from Croatia just for the day! I visited Slovenia, Montenegro and Bosnia & Herzegovina.