Dragon Valley or Monte Vista/Hidden Springs

I have all the worlds. Dragon Valley is beautiful. I use it as a medieval world. It has a lot of unique buildings and characters. There is also plenty of space. There is the added bonus that you can use houseboats in the water, if you have the expansion that adds them. I love the look of Monte Vista, but I do not enjoy it as much as Dragon Valley. I absolutely adore Hidden Springs. It is a more compact world and is easier to navigate. I do change the rabbit holes to give it a different look. There are hints of a back story about the fountain and why some of the townsfolk are green. I never really spent any time trying to make a story about that. What I really enjoyed was putting the hot air balloon from Aurora Skies up on the top lot of Hidden Springs. I always took my sims there for romantic views.

As it seems that you were drawn to the more exotic worlds first, you would probably enjoy Dragon Valley the most. That's just the opinion of someone who doesn't really know you though. :D