What dog breed is right for me? (St. Bernard, Tibetan Mastiff, Newfoundland?)?

I love my childhood dog, a 150 lb female St. Bernard. Everything about it is perfect for me (except the slobber). What other dogs are comparable to a St. Bernard? I like the looks of the Tibetan Mastiff and the Newfoundland. I just really like the gigantic but laid back, lovable dogs that couldn't hurt a fly. Dogs I hate: little ones, ones that bark.