Risen (pc, 2009) is good (very good for a budget production), but the pirates are all stuck on an island, so it plays a lot like other land-based fantasy rpgs. You should only play the pc version, though. Piranha Bytes outsourced the 360 version and that didn't go so well. There are reviews all over the place, including Youtube. Check out a few. I picked up my copy from Steam and am having fun with it.
Risen 2 should be coming early next year. Keep an eye out. Should be decent on all platforms since PB is doing all of the development in-house.
--Piranha Bytes could be called a niche developer: they started the Gothic franchise but had a falling out with publisher JoWooD and lost the rights to the Gothic name. When they went forward with their next project, they changed from "fantasy-with-a-twist" to a full-blown "pirate" theme. They're really interesting, but you have to remember that they're not giants like Bethesda or Bioware.