I've been to Dubrovnic once and I loved it! Locals weren't so happy to see tourists back then (since they'd just survived from the war) and were a bit rude, but I think that has probably changed since.
The water is so clear that it felt a bit unreal (we are used to dark lakes here in Finland). I heard that many Italians spend their holidays there but I'm not sure of it's true or not. And I've heard many compliments of Split as well! So tell us what u think if you go there too.