I grew up with German Shepards when I was younger (had two). Then when I was in high school, my mom got herself a little terrier that is probably the smartest dog I've ever been around, which is hard for me to say since I'm partial to big dogs. Blitz and Slider were great dogs though, if you want protective, but smart bigger dogs get a German Shepherd.
Realize since it's your wife's dog YOU will be the one scooping up the land mines every day. For this reason alone I suggest avoiding large dogs.
Best dogs ever. Not too small and obviously not too big. I have two, one is a "champion" breed, he was $500. Other one is just normal I guess? She was $175 I think. I absolutely love them and I can't think of anything bad about either of them.
I bought a a corgi mix. Funniest looking dog ever. It had the corgi body and legs, had the markings of a shepherd, and floppy ears. Smartest dog I have ever owned. It lived to be 16, and cried out loud when he died. I literally took 2 days off work because I was so sad. Corgi's in general are considered outstanding dogs anyway
Corgis are already funny looking so that must have been hilarious! My dogs are way smarter than other dogs I have been around and they are always nice.
We have a Labradoodle. Best dog I've ever owned. Great temperment, doesnt shed, and just a kick ass dog. Everyone loves him.
Again it depends on the purpose for getting the dog. Mutts make terrible meat. I recommend selecting the recipe first then choose the appropriate breed of dog.