Two Worlds II was actually my intro to the series, but I only played it long enough to reach the point where you're allowed to freely roam the island.
Finished this one just a while ago. The soundtrack is awesome. Otherwise the game is a mixed bag. Beautiful and yet a little shallow. Big and yet over too soon. And the final battle is shit. Really. But the expansion Pirates of the Flying Fortress is totally worth it (you can continue your character from the main game). It's a lot more focused and though-out and the soundtrack is even more awesome.
The only thing that bothered me was that the main character who is quite taciturn throughout the main game (a trait that I loved!) is a little more talkative and nice. A minor gripe, really.