Re Newfoundlans : they're not dogs for everyone, because they're BIG. BIG BIG BIG. So if you don't like big dogs it's not a good idea. I see a lot more Labs around but I don't know much about their personalities.

True, Newfs are BIG, they eat a lot, vets charge more to board them and they slobber. You can always tell a newf owner because they carry a rag in their pocket!
Labs, once out of puppyhood (when they are high energy) turn into really laid back couch pooches. In general they have few things on their minds : FOOD, catching the ball, getting into any water available,sleep.
Two pretty good links:
http://www.canismajor.com/dog/newf.html
http://www.canismajor.com/dog/labrador.html