I may be too late replying to you, and if so, I hope you are enjoying your R&R somewhere warm. I'm an ex-pat living in the former Yugoslav Republic at the moment, and understand what kind of experience you may be looking for. Diving in Croatia is pretty good, due to excellent vis., and the season runs roughly from May or June to the end of September. The water can be pretty chilly in the beginning of the season, but most shops have 7mm wet suits for the cooler months if you don't already have one.
I took a trip in February to Thailand, and it was the most wonderful experience. The people, dive boats, food, and courses I took (Rescue and EFR [PADI]) were the best I've ever experienced, and it was cool to just to go somewhere way different than Europe or US. I asked around, and the divers there said they would move on to experience the Red Sea at Sharm next. I think I will too, but in the meantime, my hubby and I will rack up our dives in Croatia this summer. It's all good!