There is a very intimidating but very gentle breed called
Leonberger. Those dogs are about the size of a Saint Bernard or a Mastiff but don't slobber. They are very family oriented, can be kept in an appartment (just take everything in tail height off the shelfs
) and need not as much exercise as a German Shepherd or a Doberman. Once they are trained they will protect you with the sheer mass of their body and a scaringly big mouth in a head the size of a Yorkie. On the other hand they are called the 'gentle giants'. I have had such a Leonberger and she was the best dog I ever had (before I had Yorkies of course
.) Funny thing was that her best friend was a Yorkie and it was hilarious to watch them play. Downside of this dogs is that they need to be groomed a lot and shed quite a bit in spring...